908 research outputs found
Solar Power in the Garden State
No full textThis special issue on energy and solar power in New Jersey was made possible because of the extensive portfolio of research centers and institutes at the Edward J. Bloustein School of Planning and Public Policy. Dr. Frank A. Felder, an Associate Research Professor, has been director of the School’s Center for Energy, Economic & Environmental Policy (CEEEP) since 2006. Frank is a nuclear engineer with a PhD degree from MIT, and he, along with his CEEEP colleague, Shankar N. Chandramowli, coauthored the main article in this issue of the Advance & Rutgers Report. CEEEP has worked extensively with the New Jersey Board of Public Utilities on projects, including New Jersey’s current Energy Master Plan.Shining Brightly: Bloustein's Centers of Excellence / by James W. Hughes and Joseph S. Seneca -- Solar Power in the Garden States / by Shankar N. Chandramowli and Frank A. Felder.Guest contributors include Shankar N. Chandramowli and Frank A. Felder, PhD, Director—Center for Energy, Economic and Environmental Policy at the Edward J. Bloustein School of Planning and Public PolicyReports published as Issue Paper Number 5, May 2011, in Advance & Rutgers Report, Special Issue
Microprosthema looensis Goy & Felder 1988
No full textMicroprosthema looensis Goy & Felder, 1988 (Figs. 1–3) Material examined. 1 male (cl 5.2 mm), FLMNH UF 53415, Panama, Bocas del Toro, east of Isla Bastimentos, near Cayo Coral (Coral Key), shallow sand flat with abundance of coral rubble and sponges, depth: 3 m, in crevice of large dead coral block, leg. M. Leray, A. Anker & E.C. Rodriguez Guerra, 23 July 2018 [fcn 18-002]; 1 female (cl 4.7 mm), FLMNH UF 53416, Panama, Isla Mamey near Isla Grande, shallow reef flat with strong current, depth: 1.5 m, under large flat piece of coral rubble, leg. A. Anker, 1 August 2018 [fcn 18-007]. Distribution. USA: Florida Keys (Goy & Felder, 1988); Panama: Bocas del Toro and Isla Mamey near Isla Grande (present study). Remarks. The morphological characters of the two Panamanian specimens agree well with those described by Goy & Felder (1988) for M. looensis: (i) carapace covered with numerous blunt to subacute teeth (Fig. 1A, B); (ii) cervical groove distinct (Fig. 1B); (iii) third pereopod with teeth on both carpus and merus (Fig. 1G); (iv) most of the third pereopod surface pubescent, i.e. covered with fine, hair-like setae (Figs. 1G, 2B; see also Goy & Felder 1988: fig. 7D); and (v) pleonites sculptured and armed with blunt teeth (Fig. 1E). Goy & Felder (1988) described and illustrated the rostrum of the holotype, which has two distal (= pre-orbital) teeth on the dorsal margin and no teeth on the ventral margin. However, in the Panamanian specimens, the rostrum is rather variable: the male has three pre-orbital teeth on the dorsal margin and one tooth on the ventral margin (Fig. 1A, C), whilst the female possesses two small pre-orbital teeth and one small subapical tooth dorsally and two small subapical teeth ventrally (Fig. 1H). According to Goy & Felder’s (1988) illustrations of the holotype, none of the teeth on carapace attains the post-orbital margin, whereas the Panamanian male has two particularly large teeth that reach slightly beyond the post-orbital margin in dorsal view (Fig. 1B). The previously unknown male thoracic sternum (Fig. 1D), pleon (Fig. 1E) and third pereopod (Fig. 1G) are shown to complete the original description of M. looensis. The third pereopod is noticeably stouter in the Panamanian male than in the Panamanian female (Figs. 2A, 3), but not significantly stouter than in the ovigerous female from Florida (holotype, cf. Goy & Feder 1988: fig. 7D). We also noted some rather minor differences in the armature of the third pereopod, for example, between the Panamanian male and the holotype. For instance, in the holotype, the dorsal surface of the merus of the third pereopod bears two adjacent teeth subdistally, whilst in the Panamanian male, it has only one tooth (cf. Fig. 1G and Goy & Felder 1988: fig. 7D). The ventral surface of the merus in both the holotype and the Panamanian male has two large widely spaced teeth, however, in a slight different positions (cf. ibid.). Similarly, in the holotype, the dorsal surface of the third pereopod carpus is armed with a series of small teeth in its proximal half and one larger tooth at about its 0.7 length (Goy & Felder 1988: fig. 7D). In contrast, in the Panamanian male, the configuration of the dorsal carpal dentition is fairly different, with two larger and several smaller teeth, in addition to a stout distal tooth (Fig. 1G). However, all these differences can be interpreted as intraspecific variation, which indeed seems to be common in the genus Microprosthema (Goy & Martin 2013). Goy & Felder (1988) described and illustrated the mandible of the holotype of M. looensis. The mandibular palp of the holotype is subdivided, according to the authors, into two distinct articles, the peduncular article and the expanded terminal article (Goy & Felder 1988: fig. 6B, C). However, the presence of a two-articulated palp in the mandible of M. looensis contradicts previous observations made in various other stenopodidean taxa, the vast majority of which are characterised by the presence of a three-articulated palp (Goy 2010: fig. 65.6; but see Quintal & Goy 2019: fig. 2F). Therefore, one of the mandibles of the Panamanian male was dissected and its palp illustrated (Fig. 1F) for comparison with that of the holotype. Interestingly, the mandibular palp of the male shows the typical three-articulated condition, as described for most other species of Microprosthema and Stenopodidea in general. Thus the biarticulated mandibular palp of the holotype of M. looensis may be an aberrant condition of that specimen or at least may be viewed as untypical for the species. The colouration of M. looensis was briefly described by Goy & Felder (1988) as “Carapace and abdomen [= pleon] whitish tan; antennae, telson, uropods, and all appendages white. Eggs are pale green”. This description was possibly based on a superficial observation of the living shrimp against a solid black background. The carapace, pleon and third pereopods of both Panamanian specimens are pale pink with a slight yellowish tinge (Figs. 2, 3), which is due to the presence of numerous, scattered, small, red chromatophores, visible only under a dissecting microscope or with a digital camera zoom. The tail fan, antennular and antennal flagella, and all other appendages (first and second pereopods, ambulatory pereiopods) are white to semi-translucent with a pale yellow tinge (Figs. 2, 3). Microprosthema is represented by five other species in the western Atlantic, in addition to M. looensis. These species are: M. granatense Criales, 1997, M. inornatum Manning & Chace, 1990, M. manningi Goy & Felder, 1988, M. semilaeve (von Martens, 1872) and M. tortugasensis Goy & Martin, 2013 (Goy & Felder 1988; Criales 1997; Goy & Martin 2013). Although De Grave et al. (2016) questioned the presence of M. inornatum in the western Atlantic, based on a single record from a deep-water locality (63–110 m) in the Gulf of Mexico (Goy & Martin 2013), Dr. Joseph W. Goy (pers. comm.) confirmed the identity of the specimen in question (USNM 1541992) as M. inornatum. Microprosthema looensis is the only western Atlantic species with the carapace densely covered with spines, the third pereopods pubescent, and the pleon sculptured and armed with small scattered spines (see also key in Goy & Martin 2013). It is also the second species reported from Panama, together with M. semilaeve, which is much more common on shallow sand flats with abundant coral rubble (De Grave & Anker 2017).Published as part of Ferreira, Luciane Augusto De Azevedo, Leray, Matthieu & Anker, Arthur, 2020, New findings of the stenopodidean shrimp Microprosthema looensis Goy & Felder 1988 (Decapoda: Stenopodidea: Spongicolidae), pp. 445-450 in Zootaxa 4729 (3) on pages 445-449, DOI: 10.11646/zootaxa.4729.3.11, http://zenodo.org/record/363274
Cooperative Learning in a Sequence of Engineering Courses: A Success Story
No full textThis paper, from Richard M. Felder, the Hoechst Celanese Professor of Chemical Engineering at North Carolina State University, cover cooperative learning in engineering courses. Cooperative learning is explained, as well as a chronology of its implementation by the author, and an summative evaluation of the experiment.&nbsp
How About a Quick One?
No full textIn this article, the author discusses the advantages of active teaching and learning methods vs. chalk and talk traditional teaching with particular relevance for technical courses. Felder describes formats and strategies for small-group in-class exercises and producing the one-minute paper
Pugnatrypaea emanata Felder & Robles 2020, n. sp.
No full textPugnatrypaea emanata n. sp. (Figs 1 A–J, 2A–M, 3A–E) Callianassidae (an undescribed genus).– Martin & Haney 2005:500. Callianassa ? sp. GMX-1, GMX-2.– Felder & Robles 2009: 336, 339, fig. 1 (part), table 1 (part). Pugnatrypaea GMX.– Robles et al. 2020 (in press: proof pages D, F), figs 1, 3, suppl. tables 1, 2. Pugnatrypaea GMX.– Poore et al., 2019: 35, fig. 6j. Type material. Off Louisiana and Texas, U.S.A. (northwestern Gulf of Mexico). Holotype: male (photograph voucher), pocl 8.6 mm (USNM 1559553 = ULLZ 17962), near Bush Hill hydrocarbon seep, 0.25-m² box corer sample, 560 m depth, 27° 46.829’ N; 91° 30.387’ W, soft silty sulfurous mud releasing globules of waxy crude oil and oily surface sheen, 1 August 2002, D.L. Felder & R. Robles. Paratypes: 1 male, pocl 4.7 mm (USNM 1559376 = ULLZ 17961), near Bush Hill hydrocarbon seep, sieved from multi-corer sample, 590 m depth, 27° 46.829’ N; 91° 30.387’ W, soft silty mud, 31 July 2002, C. Allan, S. Brooke, D.L. Felder, & R. Robles; 1 male (photograph vouch- er), pocl 6.6 mm (USNM 1541301 = ULLZ 6058), near Bush Hill hydrocarbon seep, 0.25-m² box corer sample, 560 m depth, 27° 46.829’ N; 91° 30.387’ W, soft silty sulfurous mud releasing globules of waxy crude oil and oily surface sheen, 1 August 2002, D.L. Felder & R. Robles; 1 ovigerous female, pocl 8.8 mm, embryo diameter 0.50–0.54 mm (USNM 1543631 = ULLZ 8279) benthic skimmer, 610–850 m depth, station NSF-III-074, 28° 06.52’ N; 89° 46.57’ W, mud, 8 July 2006, D.L. Felder, S. Fredericq, et al.; 1 ovigerous female (photograph voucher), pocl 7.8 mm, embryo diameter 0.61–0.68 mm (USNM 1543633 = ULLZ 8280) benthic skimmer, 610–850 m depth, station NSF-III-074, 28° 06.52’ N; 89° 46.57’ W, mud, 8 July 2006, D.L. Felder, S. Fredericq, et al.; 1 ovigerous female (photograph voucher), pocl 8.1 mm, embryo diameter 0.47–0.64 mm (USNM 15433634 = ULLZ 8281) benthic skimmer, 610–850 m depth, station NSF-III-074, 28° 06.52’ N; 89° 46.57’ W, mud, 8 July 2006, D.L. Felder, S. Fredericq, et al.; 1 male (photograph voucher), pocl 8.6 mm (USNM 1543632 = ULLZ 8282) benthic skimmer, 610–850 m depth, station NSF-III-074, 28° 06.52’ N; 89° 46.57’ W, mud, 8 July 2006, D.L. Felder, S. Fredericq, et al.; 1 male, pocl 6.7 mm (TAMU/ TCWC 2-3269) benthic skimmer, 732 m depth, 27° 35’ N; 95° 23’ W, 20 November 1968, W.E. Pequegnat & L.H. Pequegnat. Diagnosis.–Carapace with narrow triangular spiniform rostrum, low rounded shoulders lateral to eyestalks forming orbits; dorsal oval well defined. Eyestalk elongate, subrectangular, distomedial corner produced into round- ed prominence, cornea poorly defined. Antennular peduncle much shorter than antennal. Second maxilliped small, narrow, straplike exopod carried closely against internal surface of endopod, distinctly shorter than endopodal merus. Third maxilliped lacking exopod, row of spiniform teeth forming distinct crista dentata on internal surface of ischium. Major chela with inferior keel of merus bearing proximal hooked spine or spined lobe, propodus external surface with multidenticulate lobe or tubercle extending over base of gape between fingers. Pleonal tergites mostly glossy smooth, enamel-like, first crossed by dorsal transverse furrows, broad oblique furrow on ventrally directed posterolateral lobe, second somite almost twice length of first. Male first and second pleopods uniramous, each composed of two articles, terminal article of first elongate, suboval, vestigial second male pleopod narrowly straplike. Female first and second pleopods biramous. Third through fifth pleopodal endopods each with short stubby appendix interna extending clearly beyond margin. Telson elongate subrectangular, posterior margin distinctly bilobate, lobes posteriorly separated by deep incision accommodating distinct median spine. Uropodal endopod broad, about 1.5 times longer than broad, dorsally with several stiff bristles distributed along longitudinal median ridge and posterolateral surface; exopod anterodorsal plate not reaching to distal endopod margin, elongate setae of exopod distal margin grading distomesially to dense line of heavy spiniform bristles. GenBank Accession numbers for paratypes, USNM 1541301 = ULLZ 6058: (16S) EU882915, (12S) EU875025, (H3) MN 238262; USNM 1543631 = ULLZ 8279: (16S) EU992932, EU882933; (12S) EU87542, EU87543, (H3) MN 238300. Description.–Carapace frontal margin with acute, narrowly triangular rostrum, flexure weakly sinuous in lateral view, terminally spiniform, tip slightly upturned, reaching at least 2/3 length of eyestalks in dorsal view, rostral base flanked laterally by low, rounded shoulders forming orbits (Figs 1A, B; 3A, B, D, E); dorsal oval well defined, weak median tubercle in anterior 1/5, oval length about 2/3 total post-rostral carapace length; marginal furrow of oval becoming obscure at post-rostral midline, strong posteriorly at sclerotized articulation to inflated cardiac region. Eyestalks elongate, tips reaching to penultimate article of antennular peduncle, strap-like, carried slightly deflected, subrectangular in dorsal view; distomedial corner produced into rounded prominence (Fig. 1A); medial borders of stalks meeting along straight line, closely opposed; dorsal surface with very shallow longitudinal sulcus, corneal pigment variably defined, poorly faceted, dark pigmentation dispersed into multiple spots or somewhat coalesced. Antennular peduncle shorter and not strikingly heavier than antennal peduncle, reaching to or almost to proximal end of distal article of antennal peduncle (Fig. 1A); second article much shorter than basal, third article about 2.5 times length of second; second and third articles with ventromesial and ventrolateral rows of long, distoventrally directed setae. Antennular flagellum dorsal and ventral rami much longer than third article of peduncle, ventral with much longer setation than dorsal ramus; dorsal ramus heavier than ventral, especially in distal 1/3 where subterminal articles much broader than those of ventral ramus, articles there fringed with, dense ventral aesthetascs. Antennal peduncle reaching about to midlength of antennular flagellum rami; basal article dorsolateral carina arched to form lip above excretory pore; length of second article about twice width, distal articulation to third article overreached dorsally by strong spiniform scaphocerite; fourth article slightly exceeding combined lengths of first two, slightly longer than fifth, fourth and fifth very sparsely setose; fifth article slightly narrower than others. Antennal flagellum more than 3 times longer than rami of antennular flagellum, antennal flagellum setation sparse, setae very thin, 2–3 articles in length. Mandibular palp 3-segmented, elongate third article narrow, arched, setose (Fig. 1C); gnathal lobe of mandible weakly subquadrate, distolateral shoulder rounded, incisor process with well-defined triangular corneous teeth on cutting margin, one or more minute teeth proximally, concave internal face with heavy thickened lip giving rise to terminally bifurcate molar process positioned proximal and internal to incisor teeth, a few small accessory denticles between primary teeth of molar process. First maxilla endopodal palp narrow, terminal article deflected, fringed by long thin setae (Fig. 1D); proximal endite forming rounded mesial lobe densely fringed by long setae; distal endite elongate, terminally broadened with dense setation, several closely set rows strongly spiniform, innermost row weakly hooked. Second maxilla margins setose, endopod constricted distally to form narrow deflected terminus (Fig. 1E); first and second endites each longitudinally subdivided, exopod forming large, broadly cupped scaphognathite. First maxilliped margins setose, endopod very small, rudimentary, ovoid, concealed between base of distal endite and exopod (Fig. 1F); proximal endite rounded, surface at right angle to that of distal endite, densely setose terminally; distal endite straplike, subrectangular, margins and most of external surface densely setose; exopod straplike, elongate, arcuate, completely divided by oblique suture, close-set comb of very long plumose setae on mesial margin, those immediately proximal to oblique suture longer than others, overreaching distal end and setation of distal endite; epipod shorter than exopod, broad, anterior and posterior lobes subtriangular. Second maxilliped small, margins of both rami setose; endopod merus weakly arcuate, broadest proximally, length about 3 times width, length exceeding combined length of short subcylindrical propodus and dactylus, propodus length slightly less than 1/2 length of merus (Fig. 1G); dactylus about twice as long as broad, rounded terminally; exopod narrow, straplike, carried closely against internal surface of endopod, distinctly shorter than endopodal merus, terminally rounded; epipod and vestigial branchiae lacking. Third maxilliped lacking exopod, coxa bearing short spine on inner surface just proximal to articulation with ischium (Fig. 1H); endopod fringed by long setae, especially on mesial margins of ischium and merus, along with most of palp articles; ischium subrectangular, length about 1.25 times breadth, internal surface with slightly angled longitudinal row of spiniform teeth forming strong crista dentata, line ending in strong distal spine; merus subquadrate, slightly broader than long, about 3/5 length of ischium, internal surface with longitudinal fields of long setae proximal to articular with carpus; carpus almost as broad as propodus, both longer than broad, both with dense field of setae on internal surface, propodus distinctly ovoid; dactylus heavy, somewhat pyriform, weakly arcuate, terminally bearing long, stiff, serrate bristles. First pereopods strongly heterochelous in both sexes (Figs 2 A–C; 3A, B, D), major cheliped located on either right or left side, shape and ornamentation sexually dimorphic, all articles typically heavier, stouter, more coarsely ornamented in mature male than in female (Figs 1I, J; 2A; 3A–E); ischium slender, superior margin sinuous, inferior marginal carina armed by row of small spines or denticles, distal third of which is offset from proximal by slightly enlarged tooth or spine; merus superior margin with evidence of shallow depression in proximal 1/3, with or without one or more small denticles proximal to depression, inferior (flexor) margin forming microdenticulate keel, weakly bowed in distal half, variable heavy proximal hooked spine or sculpted lobe at base of keel, terminated in single acute tip or with ancillary subterminal spine or small denticles; carpus broad, subquadrate, superior and inferior margins keeled, superior margin lined by short setae, terminating distally at rounded corner, inferior margin lined by close-set row of long setae, terminating distally in acutely to subacutely angular corner; propodus broad, heavy, length of postdactylar palm subequal to or greater than length of carpus, length of fixed finger about 2/3 to 3/4 length of palm, superior and inferior margins forming keel proximally, inferior margin with rows of punctae to internal and external sides bearing tufts of long setae, much more so than along superior margin, palm externally bearing distal multidenticulate lobe or heavy tubercle extended over base of gape between fingers (strongest in mature male), prehensile edge of fixed finger lined by distally diminishing row of uniform low denticles, submarginal longitudinal depression to internal side of edge, separating edge from weak low secondary margin, tip very weakly upturned; dactyl superior margin with raised proximal tubercles and array of large punctae bearing tufts of long setae extending to near tip, prehensile edge with conspicuous U-shaped proximal notch, remainder lined by uniform low denticles diminishing in size distally, deep submarginal longitudinal depression to internal side of edge, separating edge from strong secondary margin, external side marked by row of large punctae bearing tufts of long setae, tip strongly hooked. Minor cheliped ischium narrowly elongate (Fig. 2B), inferior margin at most weakly serrate; merus subrectangular, unarmed; carpus narrow at proximal articulation, elongate with parallel superior and inferior margins distally, length slightly less than twice length of palm (Fig. 2B, C); inferior margins of carpus and propodus bearing much longer, denser setae than superior; fixed finger length subequal to or greater than length of palm, fixed and movable fingers basally broad, closely opposed, minimal gape, tips acute. Second pereopod chelate, flexor margin of merus, distal flexor margin of carpus, inferior margin of propodus lined by long regularly spaced setae, those of fixed finger becoming distally shorter and more hooked (Fig. 2D); outer surface of dactylus and distal propodus covered by tufts of long setae. Third pereopod merus length about 3 times width; propodus with inferodistal margin trilobate distal to broad proximal heel, distal lobe broadest, distal margins of lobes and heel densely lined by elongate setae (Fig. 2E), most of external surface covered by tufts of short setae; dactylus tear-shaped, superior margin concealed by long dense setae on outer surface, internally evident as slightly sinuous, article terminating in elongate, narrow, laterally directed corneous spine. Fourth pereopod very weakly subchelate, inferodistal process of propodus (= fixed finger) developed as a low densely setose rounded lobe extending distally less than 1/5 length of dactylus, lobe terminally including several very coarse, marginally serrate bristles among dense setae, these somewhat flattened and weakly channeled along one side, at least one larger than all others (Fig. 2F); dactylus elongate, weakly sinuous, tapering distally, tip twisted to terminate in well developed ventrolaterally directed triangular corneous tooth. Fifth pereopod minutely chelate terminally amid dense setation, opposable surfaces of fingers slightly spooned, terminally rounded (Fig. 2G); propodus with dense field of long, close-set setae on internal surface. Branchiae limited to pair of arthrobranchs on third maxilliped and each of first through fourth pereopods. Pleonal tergites glossy smooth, enamel-like dorsally (Fig. 3A, B, D, E). First pleonal tergite well sclerotized dorsally, crossed by distinct transverse furrow in anterior half, sclerite extended posteroventrally as broadly furrowed linguiform lobe (Fig. 1B). Second tergite almost twice length of first, anterior quarter cut by deeply incised furrow running dorsoventrally, furrow dorsally becoming obsolete, tergite ventral margin almost straight, weakly bowed, posterolateral lobe with scant setation limited to linear tuft. Third to fifth tergites each with very broad field of very fine soft setae overlying posterolateral lobe, that of third more posteriorly restricted than those on fourth and fifth, which originate near midlength. Sixth tergite with distinct posterolateral groove and short suture defining posterolateral lobe, suture not extending across tergite, lobe with submarginal tuft of stiff setae posterolaterally, separated from remaining posterior margin of tergite by similar tuft to mesial side of lobe (Fig. 2L, M). Ventral surfaces of pleonal somites mostly membraneous, lacking extensive armor of sclerotized plates or dense tubercles embedded in integument. First and second pleopods of male uniramous, each composed of 2 articles (Fig. 2H, I); first less than 1/5 length of third, elongate terminal segment subovoid, sparsely setose with few elongate setae distally; second minute, vestigial, narrower, about ¾ length of first. Second pleopod of female biramous (first not intact in available preserved specimens); exopod with scattered elongate setae, very narrow, bowed, reaching about to end of endopod when flexed against it, endopod with tuft of elongate setae, including at tip of very narrow appendix interna (Fig. 2J). Third to fifth pleopods forming large, posteriorly cupped fans, endopod of each subtriangular with short heavy appendix interna projecting distinctly from mesial margin, opposed surfaces on appendix internae of two sides each with small field of microscopic hook setae (Fig. 2K). Telson elongate subrectangular, length slightly exceeding width Figs 2L, M; 3A, D), lateral margins with weakly projecting lateral lobes in anterior 1/4, margins weakly converging posteriorly, posterior 1/3 of margin bearing pair of weakly hooked corneous spines on each side; posterior margin distinctly bilobate, lobes separated by deep posterior incision accommodating distinct median spine; dorsal surface with weak median elevation in anterior 1/3, bearing somewhat bilaterally separated fields of stiff setae or spiniform bristles. Uropodal endopod broad, subrectangular, about 1.5 times longer than broad, posterior margin with continuous fringe of long setae replaced distolaterally by line of stiff spiniform bristles, dorsally with several stiff bristles distributed along longitudinal median ridge and posterolateral surface (Fig. 2L, M); exopod anterodorsal plate well developed, distally not reaching to endopod margin, posterodistal edge of plate lined by short, thick, spiniform bristles grading distolaterally to thinner, dense, elongate setae of exopod distal margin, very long distal setation grading distomesially to dense line of heavy spiniform bristles. Color.–Little coloration in life (Fig. 3 A–E), sclerotized major cheliped mostly opaque white, antennal peduncles, rostrum, eyestalks, minor cheliped, and proximal articles of other pereopods translucent whitish. Body otherwise mostly translucent horn to pale olive, with narrow tracts of translucent whitish along sclerotized margins of somites. Embryos pale orange to yellow. Size. –Largest male pocl 8.6 mm; largest female pocl 8.7 mm; range of embryo diameters, measured as greatest dimension, 0.50–0.68 mm. Habitat.–Soft muds and silts (Fig. 4A, C, D), including those in immediate vicinity of hydrocarbon (methane) cold seeps, outer continental shelf and upper slope, 560 to at least 732 m depth. Distribution.–Western Atlantic Ocean, northwestern Gulf of Mexico, outer continental shelf off Louisiana and Texas. Etymology.–The species name “ emanata ” is an adjective derived from the Latin “emanare”, meaning to ooze or flow out, alluding to the hydrocarbon seeps with which this species is often associated. Remarks.–Preliminary molecular genetic analyses (Felder & Robles 2009) provided evidence that this unnamed species might warrant a generic assignment other than Callianassa s.s., though no obvious alternative assignment was at the time available. More recently, comprehensive molecular phylogenetic analyses supported by morphological re-evaluations (Robles et al. 2020), have underpinned major taxonomic revisions of Callianassidae at the generic level (Poore et al. 2019). Among several new callianassid genera established in the latter work, Pugnatrypaea was shown to include “ Pugnatrypaea sp. from the Gulf of Mexico ”, the species herein named as P. emanata n. sp. Additionally, this genus now includes, under revised name combinations, Pugnatrypaea bicauda (Sakai, 2010) from 73 m depth in the Gulf of Tonkin, Vietnam; Pugnatrypaea intermedia (De Man, 1905) from 330 m depth in the Bali Sea, Indonesia; Pugnatrypaea iranica (Sepahvand, Momtazi, & Tudge, 2015) from 40–50 m depth in the Persian Gulf, Iran; Pugnatrypaea lobetobensis (De Man, 1905) from 247 m depth in the Banda Sea, Indonesia; Pugnatrypaea orientalis (Spence Bate, 1888) from 28 m depth on the Arafura Shelf, Indonesia; and Pugnatrypaea pugnatrix (De Man, 1905) from 75–330 m depths in Indonesia and India, 75– 330 m. Most of these congeners are known from very few specimens, often only a holotype, and all are known to occur only in the Indo-West Pacific. Like P. emanata n. sp., all are also found only in relatively deep subtidal habitats of continental shelves, though P. emanata n. sp. appears restricted to somewhat deeper waters than reported for any of its congeners. Species of the genus represented in the molecular phylogenetic analyses of Robles et al. (2020), included only P. emanata n. sp. (therein = “ Pugnatrypaea GMX”) and P. pugnatrix, which shared a clade. The other species grouped into Pugnatrypaea were so placed on the basis of morphological characters shared with these two species (Poore et al. 2019). Among the more diagnostic of these characters are the shapes of the third maxilliped merus, third pereopod propodus, uropodal exopod, and telson. Perhaps most strikingly, the telson tapers gradually toward a bilobate posterior margin, bears a strong pair of spiniform setae on each posterolateral margin, has a deep median excavation on the posterior margin, and has a medial spine or spinule centered in the posterior excavation. While the excavate margin of the telson is obvious in all species presently assigned to the genus, yielding the bilobed shape, the median posterior spine or the pair of spiniform posterolateral setae may not be evident in all fragmentary or mutilated specimens. This is assumed to be the case in P. bicauda and P. orientalis, both known from only single, apparently incomplete, specimens lacking evidence of these features. Morphological separation of P. emanata n. sp. from its congeners draws upon the work of De Man (1928a, b), Sakai (1999; 2010; 2011), and Sepahvand et al. (2015). Distinctions can be based upon a combination of characters, including in part the relative lengths of the antennal and antennular peduncles. With the exception of P. pugnatrix, in which the antennal and antennular peduncles are of almost the same length, known members of the genus have
Artificial Roughness Encoding with a Bio-inspired MEMS-based Tactile Sensor Array
No full textA compliant 2x2 tactile sensor array was developed and investigated for roughness encoding. State of the art cross shape 3D MEMS sensors were integrated with polymeric packaging providing in total 16 sensitive elements to external mechanical stimuli in an area of about 20 mm2, similarly to the SA1 innervation density in humans. Experimental analysis of the bio-inspired tactile sensor array was performed by using ridged surfaces, with spatial periods from 2.6 mm to 4.1 mm, which were indented with regulated 1N normal force and stroked at constant sliding velocity from 15 mm/s to 48 mm/s. A repeatable and expected frequency shift of the sensor outputs depending on the applied stimulus and on its scanning velocity was observed between 3.66 Hz and 18.46 Hz with an overall maximum error of 1.7%. The tactile sensor could also perform contact imaging during static stimulus indentation. The experiments demonstrated the suitability of this approach for the design of a roughness encoding tactile sensor for an artificial fingerpad
Fragillianassa Poore, Dworschak, Robles, Mantelatto & Felder 2009
No full textFragillianassa Poore, Dworschak, Robles, Mantelatto & Felder, 2009 Fragillianassa Poore et al. 2009: 94. Type-species. Callianassa fragilis Biffar, 1970, by original designation. Gender: masculine. Included species. Fragilianassa debilis Hernández-Aguilera, 1998 (EP); F. fragilis (Biffar, 1970) (WA); and F. joeli sp. nov. (WA).Published as part of Pachelle, Paulo P. G. & Tavares, Marcos, 2020, Axiidean ghost shrimps (Decapoda: Axiidae, Callianassidae, Callichiridae Micheleidae) of the Trindade and Martin Vaz Archipelago, Vitória-Trindade Seamounts Chain and Abrolhos, off southeastern Brazil, pp. 103-126 in Zootaxa 4758 (1) on page 106, DOI: 10.11646/zootaxa.4758.1.4, http://zenodo.org/record/373084
Hexapanopeus klausruetzleri Felder & Thoma 2022, n. sp.
No full textHexapanopeus klausruetzleri n. sp. (Figs 1A–F, 2A–J, 3A–C) Hexapanopeus nov. sp. — Thoma et al. 2014: 89, table 1, 92, fig. 1. Type material. Holotype: male, cw 9.9 mm, in dead conch shell on shallow subtidal sand flat behind reef break, off south end of South Water Cay, Belize, 16°48.682´N, 88°04.968´W, snorkeling, 1 m, 3 February 2011, coll. D. Felder, R. Lemaitre, J. Felder, S. Pecnik, & C. Tudge, USNM 1546469 (= ULLZ 12526 -A). Paratypes: 1 juvenile male, cw 7.2 mm, collection data same as for holotype, USNM 1661745 (= ULLZ 12526 -B); 1 juvenile female, cw 5.2 mm, in eroded dead conch shell from deep patchy Thalassia and sponge bed, off northeast side of Twin Cays, Belize, 16°50.133´N, 88°05.852´W, snorkeling, 4 m, 21 April 2015, coll D. Felder, J. Scioli, K. Barkel, J. Felder, & C. Craig, USNM 1549828 (= ULLZ 16524). Diagnosis. Carapace dorsal surface weakly convex, ovoid to weakly subhexagonal outline, wider than long (including anterolateral teeth), fronto-orbital width slightly exceeding 0.6 carapace width; front broadly convex with small median V-shaped notch separating shallow unimarginate lobes to each side, frontal margin of each lobe bearing slightly enlarged granules, lateral tooth of each frontal lobe obsolesent, lateral margin deflected to intersect antennal sinus; dorsal regions weakly defined, furrows of mesogastric, gastric, and anterior cardiac most evident; five anterolateral teeth, first tooth (outer orbital corner) subacutely angular, weakly separated from lobiform second by shallow depression of margin, third and fourth broadly lobiform to somewhat rounded or subrectangular, fifth small, subacutely angular. Third maxilliped merus distal margin sinuous, slightly produced to form small prominence near articulation with carpus. Cheliped merus superolateral margin with rough row of denticles, variably grouped to form serrate teeth, in major cheliped some forming sharp serrate teeth; carpus superior and lateral surfaces smooth to minutely granulate, microgranules forming weakly defined lines or surmounting weak elevations, supero-external surface marked by depression parallel to distal margin, internal margin with proximal angle weak, surmounted by line of low granules, distal angle stronger, forming blunt distally directed tooth. Major chela propodus mostly smooth to microgranulate, superior longitudinal crest weak, unarmed, adjacent external furrow shallow; dactylus opposable margin with slightly enlarged, lobiform basal tooth proximally. Ambulatory pereopods 2–5 relatively narrow, 2–4 subequal in size, merus length in all greater than 3 times greatest width, merus length approximating or slightly exceeding 1/2 carapace length; pereopod 5 smaller, propodus stouter than in other ambulatory pereopods, merus length not exceeding 1/2 length of carapace; merus in all ambulatory pereopods with superior margin unarmed, at most with dentiform granules variably concealed by plumose setae, inferior margin finely granulate; carpus superior margin with dense tract of short stout papilliform setae along crest; propodus superior margin with dense field of papilliform setae, dactylar-propodal locking mechanism not developed; dactylus stout proximally, inferior margin lacking subterminal prehensile tooth, superior margin densely covered by short papilliform setae, inferior margin with less dense slightly longer stiff simple setae. Male anterior thoracic sternum length (sternites 1–4) about 2/3 greatest width of fourth sternite (including episternites), eighth sternite exposed in subquadrate gap between lateral margin of flexed second pleonite and pereopod 5 coxa, exposure narrowly extending to anterior of condyle. Pleon of male with third through fifth pleonites fused, widest reach of first pleonite at its articulation with carapace, laterally rounded to articulation with second pleonite; telson subtriangularly rounded, widest in proximal one-third. Male first gonopod tip of highly modified panopeid form, subterminal tooth triangular, trunk in distal 1/4 of pleonal side bearing elongate field of heavy, rounded tubercles and granules extending to base of subterminal tooth. Male second gonopod less than one-third length of first gonopod. Applicable GenBank sequence accession numbers from Thoma et al. (2014) as follows for USNM 1546469 (= ULLZ 12526-A, holotype): (12S) KF683061; (16S) KF682952; (18S) KF682930; (COI) KF682772; (ENO) KF682722; (H3) KF682613. Description. Carapace (Figs 1A, B; 3A–C) about 1.3 times wider than long, dorsal surface weakly convex, transverse edges of frontal lobes unimarginate, frontal width slightly exceeding 0.5 fronto-orbital width, frontoorbital width slightly exceeding 0.6 greatest carapace width, dorsal outline ovoid to slightly subhexagonal, dorsal regions overall weakly marked by furrows, marginal furrows of mesogastric, gastric, and anterior cardiac regions evident, most others obsolescent, dorsal surfaces of frontal regions less elevated than those to posterior, transverse ridges of granules weak to obsolescent, dorsal surfaces appearing mostly smooth with low cover of small granules, densest and largest granules developed near frontal and anterolateral margins; frontal margin overall broadly convex, small V-shaped median notch separating shallow unimarginate lobes to each side, each with transverse tract of slightly enlarged granules along frontal margin, lateral tooth obsolescent (weakly evident in small specimens), forming rounded corner, lateral margin of front deflected, angled to intersect antennal sinus just below mesial end of tooth on supraorbital margin; supraorbital margin granulate, forming low obtuse tooth above antennal sinus, median and lateral fissures forming distinct breaks in marginal granulation, margin convex between fissures. Anterolateral teeth well developed along distinctly convex arch of granulate margin, granules strong along anterior slopes of teeth; anterior two of five teeth broadly fused into subquadrate prominence, first (outer orbital corner) subacutely angular, very weakly separated by shallow depression of granulate margin from weakly lobiform second; third slightly produced at coarsely granulate anterior angle, lateral margin convexly rounded; fourth broadly triangular to subquadrate, angular anterior tip subacute, lateral margin weakly convex; fifth small but distinctly developed, subacutely angular. Posterolateral finely granulate with sparse cover of elongate plumose setae. Infraorbital margin (Fig. 1B) granulate, forming strong subtriangular tooth mesially below base of eyestalk, margin sinuous laterally, ending in weakly produced infraorbital tooth. Pterygostomial and subhepatic regions with scattered low granules, coarsest near margins and along outer subhepatic region, lacking enlarged subhepatic tubercle, pterygostomial ridge distinctly granulate, slightly raised. Branchiostegite posterolaterally with sparse cover of elongate plumose setae, partially concealing ventrolateral margin above coxae of ambulatory legs. Eyestalk stout, anteriorly with short precorneal patch of enlarged, raised granules. Antenna with long flagellum, peduncle with fused basal article elongate, rectangular, extending into orbital fossa. Third maxilliped (Fig. 1C, D) protopod elongate, distal surface weakly grooved to intersect ventral edge of carapace, bearing pair of unequal projections along margin internal to groove, proximal to small podobranch gill positioned adjacent to pair of much longer, lamellate, arthrobranch gills. Epipod thin, flattened, strap-like, bearing long simple setae along length. Endopod basis subtriangular; ischium broadly subrectangular, proximal end curved laterally to intersect basis, external surface mostly smooth with few small, granules densest marginally and in external tract along distomesial margin, weak evidence of longitudinal furrow medially, mesial margin with sparse fringe of simple setae; merus subquadrate, lateral margin near straight to very weakly concave, distolateral margin weakly angular to rounded, distal margin sinuous, produced to form distinctly raised tooth-like prominence near articulation with carpus, obliquely excavate distomesially to accommodate articulation and flexure of carpus, internal surface with short transverse tract of mesially directed setae extending into excavation below articulation of carpus; carpus short, stout, internal surface with distal fringe and distal submarginal field of elongate setae overlying propodus; propodus cylindrical, internal, superior, and inferior surfaces distally with submarginal and distal rows of elongate, stiff setae; dactylus elongate, digitiform, tapering distally, length about 1.5 times that of propodus, internal surface and inferior margin bearing short stiff setae, tip bearing dense tuft of long stiff setae approximating length of dactylus. Exopod weakly arched, elongate, narrowly subrectangular, internal edge of mesial margin produced to form strong rounded subtriangular projection in distal third, flagellum multi-articulate, bearing numerous long, distally directed setae. Chelipeds (first pereopods) (Figs 1E, F; 3A–C) somewhat unequal, texture mostly smooth or minutely granulate, few setae overall, slightly more setose along some margins of merus and carpus; ischium and merus with few plumose setae along tracts of enlarged granules on inner margins, small dense setal tuft near proximal inner margin of ischium; merus superolateral margin with roughly defined row of denticles, variably grouped to form serrate teeth, in major cheliped some forming enlarged, sharp serrate teeth, proximally with few plumose setae; carpus superior and lateral surfaces smooth to minutely granulate, microgranules forming weakly defined lines or surmounting elevations, supero-external surface marked by distinct depression parallel to distal margin, proximal to which weakly defined ridges of microgranules on supero-external surface, internal margin with proximal angle ill-defined, rounded, surmounted by line of low granules, distal angle stronger, produced to form blunt, subtriangular, distally directed tooth. Major chela propodus mostly smooth to microgranulate, superior longitudinal crest of palm weak, unarmed, adjacent external furrow shallow; fixed finger of major chela subtriangular, exceeding ½ length of palm, inferior margin weakly convex, thick subacute tip curved upwards, opposable margin bearing five to six subtriangular to rounded teeth, proximal pair slightly fused, dark pigmentation extending proximally to base of finger but not onto palm; dactylus arched, slightly longer than fixed finger, opposable margin with slightly enlarged, lobiform, basal tooth proximally, distally with four to five somewhat rounded teeth separated by few smaller rounded denticles or granules, narrowing to subacute tip curved to cross to internal side of fixed-finger tip when flexed. Minor cheliped propodus similar to that of major in form and length, palm less robust and slightly less elevated than that of major, dorsal microgranulation slightly coarser than that of major; fixed finger of minor chela closely resembling but slightly longer than that of major, opposable margin with six enlarged triangular to subtriangular teeth, distal three most closely grouped and least acute, dark pigmentation extending proximally beyond finger slightly onto distal extreme of palm; dactylus of minor chela resembling that of major, opposable margin lacking enlarged basal lobiform tooth, cutting edge dentition slightly weaker than in major chela, five to six teeth enlarged, proximal three subtriangular, distal lower and more rounded, subacute tip crossing to internal side of fixed-finger tip when flexed. Ambulatory pereopods 2–5 relatively narrow, elongate, all of similar general form (Fig. 2A–E; 3A–C); pereopods 2–4 subequal in size, merus length in each greater than three times greatest width, length of meri approximating or slightly exceeding 1/2 carapace length; pereopod 5 smaller, propodus relatively stouter than in other ambulatory pereopods, merus length not exceeding 1/2 that of carapace; ambulatory pereopod meri all with superior margin relatively unarmed, at most bearing a few small dentiform granules variably concealed by row of elongate, plumose setae, distal superior margin ending in low, blunt angle beyond subdistal notch, inferior margin finely granulate, at most with few setae, granules coarsest, densest proximally on pereopod 2; carpus superior margin with pubescence formed by dense tract of short stout papilliform setae along crest, few longer narrower setae, crest roughly paralleling weak to obsolescent secondary crest on superoposterior surface, secondary crest stronger on fourth pereopod than others; propodus superior margin with pubescence formed by dense field of papilliform seta, few longer narrower setae, inferior margin lined by primarily short, narrow, simple setae along with few longer; dactylar-propodal locking mechanism not developed; dactylus stout proximally, narrowing in distal half to weakly falciform corneous tip, inferior margin lacking subterminal, calcareous, prehensile tooth, superior margin densely covered by short papilliform setae forming broad tract of thick pubescence, inferior margin with less dense tract of slightly longer stiff simple setae, both margins with few additional long simple setae, dactylus terminating in weakly hooked, acute corneous tip. Male anterior thoracic sternum length (sternites 1–4) longer than broad (Fig. 2F, G), length from acute anterior apex to suture between fourth and fifth sternites about 2/3 greatest width of fourth sternite (including episternites), sternopleonal depression in fourth sternite not unusually sculpted or excavate to accommodate first gonopod tips below flexed pleon, median line originating from triangular depression at posterior of fourth sternite, narrowing to smooth very shallow groove bisecting fourth sternite, becoming obsolete to anterior; fifth sternite with small granuliform tubercle (part of press-button locking system) to each side of sternopleonal depression, each centered near 3/5 of distance from sixth sternite to fourth sternite; fourth and fifth episternites narrowly angular, subtruncate to anterior, subacutely rounded to posterior, sixth and seventh episternites slightly broader and more rounded posteriorly, eighth sternite exposed only in subquadrate gap between lateral margin of flexed second pleonite and pereopod 5 coxa, exposure narrowly extending to anterior of condyle on pereopod 5 coxa. Pleon of male (Fig. 2F, G) with third through fifth pleonites fused, first pleonite widest at articulation with carapace, rounded to articulation with second; second pleonite widest proximally near articulation with first, narrowing distally; fused third through fifth pleonites widest at lateral flange of third, weakly sinuous laterally, narrowing distally, width at articulation with sixth pleonite about half that at wide flange of third, vestiges of sutures between fused pleonites obscure; sixth pleonite subrectangular, slightly broadened distally before articulation with telson; telson subtriangularly rounded, widest in proximal third. Male first gonopod tip (Fig. 2H, I) of highly modified panopeid form, subterminal tooth triangular, terminal lobes not well-separated to produce trifid appearance typical of most panopeid crabs, trunk in distal 1/4 of pleonal side bearing elongate field of heavy, rounded tubercles and granules extending to base of triangular subterminal tooth, distolateral margin bearing several stiff setae proximal to terminal lobes. Penis emerging from pore on mesial surface of pereopod 5 coxa concealed beneath seventh episternite, extending beneath lateral flange formed by base of first gonopod. Male second gonopod less than one-third length of first gonopod, narrowing to subacute tip bearing several subterminal setae (Fig. 2J). Color. The carapace and pereopods are primarily golden brown to pale orange in presently limited materials, most dorsal surfaces being speckled with scattered dark reddish brown spots (Fig. 3A–C). The pigment is overall darker on upper surfaces of chelipeds and ambulatory legs of larger specimens, especially the holotype, which is the largest. White borders the margins of most pereopod joints, and a distinct white spot is developed on the upper distal propodus on the cheliped, positioned immediately proximal to articulation of the movable finger. Fingers of the chelae vary in color from horn to reddish brown, with lighter tips. All pigmentation is pale in the most immature specimen. Etymology. The species name is assigned in recognition of Klaus Ruetzler, world authority on marine sponge biology, who also led the establishment of the Smithsonian Marine Field Station at Carrie Bow Cay, Belize and for many years directed the Caribbean Coral Reef Ecosystems (CCRE) program based there. His encouragement and support of collaborators and colleagues brought many to focus years of work in Belize, including the senior author of this paper. Size. Carapace widths ranged from 5.2 mm in the small female paratype to 9.9 mm in the male holotype. Distribution. At present known only from tropical waters in the vicinity of South Water Cay and Twin Cays along the barrier reef of Belize. Habitat. Thus far known from only high salinity shallow subtidal calcareous sand habitats (1–4 m depth), occupying dead gastropod shells on wash-over fans and back-reef flats of coral reefs, sometimes between patches of turtle grass and sponges. Remarks. Systematic and taxonomic studies of western Atlantic panopeid crabs have been advanced over recent decades through detailed comparative studies of male gonopods (Guinot 1967, 1968, 1969a –c, 1971, 1978, 1990; Martin & Abele 1986; Felder & Martin 2003). However, the advent of molecular genetic analyses has provided yet another powerful tool of particular value in understanding of phylogenetic relationships among otherwise very similar appearing panopeid crabs (Schubart et al. 2000, Thoma et al. 2009; Thoma et al. 2014; Felder & Thoma 2020). Thoma et al. (2014: 98), on the basis of molecular genetic analyses, concluded that confirmed membership of Hexapanopeus s.s. was restricted to very few species, with the only two named species at that time being the western Atlantic H. angustifrons and H. paulensis Rathbun, 1930. Their analysis also included several undescribed lineages, one of which is herein represented by H. klausruetzleri n. sp. Morphologically, mature males of both the previously described congeners differ markedly in first gonopod morphology from that found in Hexapanopeus klausruetzeri n. sp. (Fig. 2H, I), the first gonopods of H. paulensis and H. angustifrons having been previously illustrated by Williams (1965: figs 183D, E). Unfortunately, no mature female specimens of H. klausruetzleri n. sp. are presently available for description and comparative study of the fully developed female gonopore, a character that can also be of utility in panopeid crab separations. However, the previously described species of both sexes differ from H. klausruetzleri n. sp. in having a carapace front that is more truncate than arcuate, and in having the first and second anterolateral teeth distinctly separated (Williams 1965: figs 170, 171) rather than weakly defined to either side of a shallow depression (Fig. 1A, B). In addition, the anterolateral teeth are overall more angular and the carpus of the major cheliped is more roughly sculptured in both of the previously described species than in H. klausruetzleri n. sp. Sculpting of the major cheliped carpus in H. paulensis is especially distinct, with its dorsal surface typically bearing 8–15 well-defined knoblike tubercles. Sculpting of the carpus in H. angustifrons, while much less pronounced than in H. paulensis, is at least somewhat rougher than in H. klausruetzleri n. sp., the species to which it has a close sister relationship in molecular genetic analyses (Thoma et al. 2014). It appears that morphological separation of the closely related tropical Hexapanopeus klausruetzleri n. sp. and warm-temperate H. angustifrons can also be based upon additional characters, though presently limited material of the new species limits knowledge of their variability. Available specimens of H. klausruetzleri n. sp., exhibit stronger dentition of the cheliped merus, with its superolateral margin armed by row of denticles, some of which are grouped to form serrate teeth that are especially enlarged and sharply serrate on the major cheliped (Fig. 1F). By contrast, this margin in H. angustifrons is armed by a low ridge ending in a blunt triangular tooth distally, bearing at most a low tubercle and one or two very weak subacute teeth along its length (TAMU/TCWC 2-2789). Additionally, H. klausruetzleri n. sp. is overall smoother in texture and ornamentation of the pereopods than is H. angustifrons. This is especially evident in the better-defined and more coarsely granulate carpal ridges in H. angustifrons, both on the chelipeds and the ambulatory pereopods (though not depicted in detail by Williams 1965: fig. 170). The broadly angular, rounded, to subrectangular shape of the anterolateral carapace dentition in Hexapanopeus klausruetzleri n. sp. is somewhat similar to that seen in subadult to adult stages of Eurypanopeus abbreviatus (Stimpson, 1860), E. ater Rathbun, 1930, and Panopeus americanus Saussure, 1857. In both E. abbreviatus and E. ater, the carapace anterolateral teeth are more consistently evident as shallow lobes, with the third being distinctly subrectangular and most of its lateral margin straight, while the anterior and posterior ends form rounded corners. By contrast, the anterol
Sayixa Theil & Felder 2020, n. gen.
No full textGenus <i>Sayixa</i> n. gen. <p>urn:lsid:zoobank.org:act: 2312947B-988C-442F-B00C-8BCBCE273BC2</p> <p> TYPE SPECIES. — <i>Sayixa monodactyla</i> (Say, 1818) n. comb. [<i>Pinnixa</i>].</p> <p> ORIGINAL DESCRIPTION FOR <i>PINNIXA</i> [<i>PINNOTHERES</i>] <i>MONODACTYLA</i> (SAY, 1818). — “ <i>P. monodactylum *</i> (male) Thorax transverse; hands monodactyle. […]</p> <p> <i>Thorax</i> transversely subeliptical, narrowing each side to the middle of the lateral edge, which is rounded, a tubercle each side marking the situation of the anterior lateral angles, surface punctured; <i>orbits</i> suborbicular; <i>anntennae</i> [sic], exteriors subequal to the breadth of the clypeus; <i>hand</i> oblong, somewhat quadrate; <i>palm</i> concave and ciliated in the middle, a spiniform angle instead of a finger, with a tooth at its base, and another at the base of the thumb larger; <i>thumb</i> abruptly incurved at base, rectilinear towards the tip, with an angle at the interior middle, tip acute, attaining the tip of the spiniform angle; <i>feet</i>, second, fifth and third pairs subequal, the latter rather larger, fourth pair larger, and with the fifth pair with somewhat dilated tibia; <i>abdomen</i> with a few larger punctures, terminal joint rounded at tip, entire, ciliated and attaining the tip of the geminate joints of the pedipalpi.</p> <p>Length three tenths, breadth one half an inch.</p> <p>This curious animal occurs in the Richmond Museum. Mr. J. Warrell, the proprietor of that interesting establishment, supposes it to be American, but whether from our eastern or western coast he could not say. It is particularity remarkable in having monodactyle hands, a character which in a very rigid arrangement would not only separate it from the genus Pinnotheres, but also from the preceding species as a distinct genus. The tibia of the fourth and fifth pairs of feet are somewhat dilated, but the corresponding tarsi are accidentally wanting in this specimen.”</p> <p>DIAGNOSIS. — Carapace transversally subeliptical, wider than long, punctate, narrowing toward rounded lateral edges; anterolateral margins each with single lobiform tooth or tubercle near or just anterior to lateral extreme. Third maxilliped with ischiomerus subtrapezoidal; propodus and dactylus elongate, longer than carpus; dactylus inserting near base of propodus, reaching beyond end of propodus. Chelipeds heavy, palm lacking longitudinal lines of setae; cheliped fixed finger strongly shortened, reduced to spiniform angle, with sharp tooth at base of dactylus.</p> <p>First two ambulatory legs (P2, P3) slender, P4 and P5 somewhat stouter; lengths P4> P3> P2> P5. Male pleon subtrapezoidal, somites 4-6 constricted; telson oblong subellipsoidal, much wider than long.</p> <p>ETYMOLOGY. — Named for Thomas Say, author of the type species of this new genus, and first author to describe pinnotherid species after Linneaus.</p> <p>MATERIAL EXAMINED. — In addition to the material included in the phylogenetic analyses (Table 1) one sample was available for examination: MNHN-IU-2017-9368 (= former ULLZ 8569) (offshore, northern Gulf of Mexico).</p> <p>REMARKS</p> <p> In describing the species <i>Pinnotheres monodacytlum</i>, later transferred to <i>Pinnixa</i>, Say (1818) indicated that this taxon presented characters that “would not only separate it from the genus <i>Pinnotheres</i>, but also from the preceding species as a distinct genus”. The “preceding species” he is referring to is <i>Pinnotheres cylindricum</i>, which would become later the type of the genus <i>Pinnixa</i>. He discusses in that work the differences between the two species and the genus <i>Pinnotheres</i>, but he chose to maintain both within the genus <i>Pinnotheres</i>. Later, in 1846, Adam White, assistant in the Zoological Deparment of the British Museum, established the genus <i>Pinnixa</i> for <i>P.cylindrica</i> on the basis of its carapace being much wider than long, its having a larger cheliped palm when compared to <i>Pinnotheres</i>, and on the relative lengths of the ambulatory legs. He, however, did not include what we herewith assign to <i>Sayixa monodactyla</i> n. comb. in the genus <i>Pinnixa</i>, most likely because he had not found the opportunity to examine it. According to Rathbun (1918), <i>Sayixa monodactyla</i> n. comb. had not been seen since the type was reported upon. Moreover, the type in Richmond Museum was, also according to her, probably not extant.</p>Published as part of <i>Theil, Emma Palacios & Felder, Darryl L., 2020, Phylogeny of the genus Pinnixa White, 1846 (Crustacea, Brachyura, Pinnotheridae) and allies inferred from mitochondrial and nuclear molecular markers, with generic reassignment of twenty-one species, pp. 85-103 in Zoosystema 42 (6)</i> on pages 97-98, DOI: 10.5252/zoosystema2020v42a6, <a href="http://zenodo.org/record/3695831">http://zenodo.org/record/3695831</a>
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