170 research outputs found
Bryconops collettei Chernoff & Machado-Allison, 2005, n.sp.
No full textBryconops collettei n.sp. (Figs. 3b, 8) Holotype. MBUCV-V-30780, 74.0 mm SL; Venezuela: Bolívar: Río Nichare at Wakawajai, tributary of the Río Caura, 6º 19 21 N 64º 57 13 W; A. Machado-Allison, F. Provenzano, A. Marcano, 6 Dec. 2000. Paratypes. All localities in Venezuela: FMNH 109350, 3 (42.8-52.4 mm SL); MBUCV-V-30781, 2 (43.1-52.6 mm SL); collected with the holotype. FMNH 109348, 2 (55.0-58.5 mm SL); Río Caura, beach in front of El Playón, 6º 19 31 N 64º 31 37 W; A. Machado-Allison et al., 3 Dec. 2000. FMNH 109347, 1 (46.0 mm SL); Río Caura, Caño at Katuwadi Chenu down-river from El Playón, 6º 19 44 N-64º 31 40 W; A. MachadoAllison et al., 3 Dec. 2000. ANSP 139597, 6 (45.9-58.0 mm SL); Río Mato, sandy beach, tributary of Río Caura, 7º 02 N 65º 14 W; J.E. Bohlke et al., 1 Feb. 1977. Additional Material (non-types). FMNH 109349, 20 (10.6-16.0 mm SL); Río Tawadu, raudal Dimoshi Soodii, tributary of the Río Caura, 6º 19 38 N-65º 02 52 W; A. Machado-Allison et al., 5 Dec. 2000. ANSP 168006, 18 (33.5-71.0 mm SL); MBUCV-V- 21791. 20 (36.0-76.0 mm SL); Río Miamo, on Guasipati-El Miamo road, 20 km S of El Miamo, Río Yuruari/ Cuyuní basin, 7º 38 N 61º 50 W; S. Schaefer et al., 24 Jan. 1991. ANSP161536, 21 (29.0-66.0 mm SL); Río Iguapo, tributary of Río Orinoco, ca. 1 hr. above its mouth by boat. 03º 09 N 65º 28 W; H. López et al., 13 Mar. 1987. Diagnosis. A species of Bryconops, subgenus Bryconops, that is distinguished from all other congeners except B. magoi by its unique color pattern, in which red coloration occupies the upper half of a diffuse caudal-fin ocellus. It is further distinguished from members of the subgenus Bryconops by the following traits: pored lateral scales 44-48, modally 47 (>57 in B. alburnoides, 6.2) than the waters in the other rivers (pH<5.7). However, this is speculation at present. As a precaution, we have restricted the types to the Río Caura populations.Published as part of Barry Chernoff & Antonio Machado-Allison, 2005, Bryconops magoi and Bryconops collettei (Characiformes: Characidae), two new freshwater fish species from Venezuela, with comments on B. caudomaculatus (Gunther)., pp. 1-23 in Zootaxa 1094 on pages 13-1
FIGURE 1 in A new species of suckermouth armored catfish, Pseudancistrus kwinti (Siluriformes: Loricariidae) from the Coppename River drainage, Central Suriname Nature Reserve, Suriname
No full textFIGURE 1. Dorsal, lateral, and ventral views of juvenile Pseudancistrus kwinti, paratype, FMNH 116975, 43.9 mm SL.Published as part of Willink, Philip W., Mol, Jan H. & Chernoff, Barry, 2010, A new species of suckermouth armored catfish, Pseudancistrus kwinti (Siluriformes: Loricariidae) from the Coppename River drainage, Central Suriname Nature Reserve, Suriname, pp. 40-48 in Zootaxa 2332 on page 43, DOI: 10.5281/zenodo.19312
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Session C6 - The Effects of Dam Removal on the East Branch of the Eightmile River, Connecticut
No full textProfessor Barry Chernoff joined the Wesleyan Faculty in 2003 where he holds the Robert K. Schumann Chair of Environmental Studies. He currently chairs the Environmental Studies Major and is Director of the College of the Environment. He teaches courses in Environmental Studies, Tropical Ecology, Aquatic Ecosystem Conservation, Quantitative Analysis and Evolutionary Biology for the departments of Biology and Earth and Environmental Sciences. Chernoff's research centers on the freshwater fishes of the Neotropical region, primarily those in South America in the Amazon. His research includes, ecology, evolutionary biology and conservation. He has also led international teams on expeditions designed to conserve large watersheds of the world, having made more than 32 expeditions in 12 countries. Recently, Professor Chernoff and his students have been working on aquatic ecology and conservation of Connecticut watersheds. In the past he has held professorial and curatorial positions at the Field Museum, University of Chicago, University of Illinois at Chicago, University of Pennsylvania and the Academy of Natural Sciences of Philadelphia. He holds visiting positions at Universidad Central de Venezuela and the Museu Zoologia de Universidade de Sao Paulo, Brasil. He has authored and co-authored 87 scientific articles and books. Chernoff has received a number of awards including the Caleb T. Winchester Outstanding Scholar and Teacher Award, 1 May 2006, awarded by Xi of Psi Upsilon, Wesleyan University and a Commendation for Excellence in Teaching, University of Chicago, 2000. Chernoff was elected to the Connecticut Academy of Sciences and Engineering in 2005, where he chaired the Environmental Science and Technology Board until 2010. From 1993-1999, he served on the U.S. National Committee for the International Union of Biological Sciences elected by the National Academy of Sciences/National Research Council, and served as Vice-Chairman from 1995-1997 and Chairman from 1997-1999.The hydrography of the East Branch of the Eightmile River has been modified since the 1720's when a dam was constructed on the Zemko property. While the dam has occasionally fallen into disrepair, the dam has largely been intact for more than the last hundred years. In 2006, the water in the impoundment behind the dam was drawn down and the dam was completely removed by fall 2007; a rocky connector was constructed between the portion above and below the former dam. We have surveyed fishes, benthic macroinvertebrates (BMI), water chemistry and physical parameters from 2004 through 2010 at the former dam sites and at a control site five river miles downstream. The biological communities have changed dramatically since drawdown and dam removal. The inter-annual variation of the communities in the vicinity of the dam site is significantly higher than at control sites. The data from both fish and benthic macroinvertebrates indicate that the patterns of change or "recovery" differ in the sections of river above and below the dam. We will ask whether there has been recovery from dam removal in this small section of stream. We will also discuss the concepts of resilience and adaptation in relation to the functioning of the streams
Bryconops caudomaculatus
No full textComparative material of Bryconops caudomaculatus. Holotype: BMNH 1852.9.13.74, South America, Zoological Society of London. Nontype material: All material from Guyana (formerly British Guiana), Essequibo Drainage: ANSP 176611 (11 specimens), ANSP 176617 (11); FMNH 69762 (122); FMNH 52943 (3); FMNH 52944 (2); FMNH 52945 (1); FMNH 52946 (26); FMNH 52947 (2); FMNH 52948 (26); FMNH 52949 (1); FMNH 52950 (6); FMNH 52951 (1); FMNH 52952 (3); FMNH 69624 (23); FMNH 69625 (4); FMNH 69696 (5); FMNH 7443 (2); FMNH 7448 (1); FMNH 7449 (5); FMNH 7450 (1); FMNH 7553 (1); FMNH 81642 (25); INHS 49391 (1); INHS 49509 (8); UMMZ 216145 (5).Published as part of Barry Chernoff & Antonio Machado-Allison, 2005, Bryconops magoi and Bryconops collettei (Characiformes: Characidae), two new freshwater fish species from Venezuela, with comments on B. caudomaculatus (Gunther)., pp. 1-23 in Zootaxa 1094 on page 2
FIGURE 4 in A new species of suckermouth armored catfish, Pseudancistrus kwinti (Siluriformes: Loricariidae) from the Coppename River drainage, Central Suriname Nature Reserve, Suriname
No full textFIGURE 4. Map of major rivers in Suriname and collection localities for Pseudancistrus kwinti (star = holotype, circle = paratype).Published as part of Willink, Philip W., Mol, Jan H. & Chernoff, Barry, 2010, A new species of suckermouth armored catfish, Pseudancistrus kwinti (Siluriformes: Loricariidae) from the Coppename River drainage, Central Suriname Nature Reserve, Suriname, pp. 40-48 in Zootaxa 2332 on page 46, DOI: 10.5281/zenodo.19312
Bryconops magoi Chernoff & Machado-Allison, 2005, n. sp.
No full textBryconops magoi n. sp. (Figs. 3c -4) Holotype. MBUCV-V-30782 (64 mm SL); Venezuela: Anzoátegui: Río Moquete at Paso Bajito, AN; L. Aguana, 4 Feb.1984. Paratypes. All lots collected at type locality, but some with different dates and/or collectors. MBUCV-V-30783, 10 (17.0-54.0 mm SL). FMNH 113936, 2 (35.5-55.5 mm SL) (preceding two series collected with holotype). MBUCV-V-30784, 2 (52.5-53.0 mm SL); A. Machado, 4 Oct.1984. FMNH 113937, 2 (40.0-45.5 mm SL); A. Machado, 4 Oct.1984. MBUCV-V-30785, 6 (56.2-69.5 mm SL); A. Machado, 1 Feb.1984. FMNH 113938, 3 (65.0-67.0 mm SL); A. Machado, 1 Feb.1984. Diagnosis. A species of Bryconops, subgenus Bryconops, that is distinguished from all other congeners except B. collettei by its unique color pattern, in which red coloration occupies the upper half of a diffuse caudal fin ocellus. It is further distinguished from members of the subgenus Bryconops by the following traits: pored lateral scales 43-47, modally 44 or 45 (>57 in B. alburnoides, <31 in B. disruptus and B. durbini, and 44-48, modally 47 in B. collettei); pored lateral scales extending 2-3 scales beyond end of hypural plate onto caudal fin rays (pored lateral scales reaching end of hypural plate and not onto caudal fin rays in B. caudomaculatus); snout length 5.8-8.0% SL, mean 6.8% (4.2-5.4%, mean 4.7% in B. collettei); length of anal fin base 24.8-27.9%, mean 26.6% (27.3-29.8% SL, mean 28.8% in B. collettei); and total vertebrae 40-42, modally 41-42 (42-44, modally 42-43 in B. collettei). Description. Morphometric data are given in Table 1 and a summary of meristic data appears in Table 2. A moderate to small-sized species of Bryconops, known from specimens less than 70 mm SL. Overall body shape with convex dorsum and slightly rounded belly, tapering to relatively short and deep caudal peduncle 10.5-13.9 (12.0 % SL). Dorsal fin origin at level of pelvic origin, almost at center of the body 49.0-52.3 (50.5 % SL). Head 23.6-27.8 (25.5 % SL); posterior margin of opercle slightly sinusoidal. Border between second and third infraorbitals with naked ventral area; third infraorbital moderatedly developed, not reaching preopercle ventrally or at angle (Fig. 5). Eye large, 8.8-11.3 (9.8 % SL). Snout bullet-shaped; mouth terminal, opening just ventral to horizontal diameter through orbit. Maxilla extending posteriorly not reaching posterior margin of the 2n infraorbital., length 5.8-8.0 (6.8 % SL). Ventroanterior margin of maxilla not heavily recurved (Fig. 5). Outer two rows of premaxillary teeth small and not prominent. Premaxilla with 2-5 teeth, bearing 3 to 5 cusps. Inner premaxillary teeth uniformly five, with 5 to 7 cusps; teeth basically symmetrical. Maxilla without teeth, rarely a small and single unicuspid tooth. Dentary with 4-5 large teeth, bearing 5-7 cusps. Smaller dentary teeth few. Dorsal fin with straight to slightly convex distal margin; either the first or second branched ray longest. Posterior base of dorsal fin separated from anterior base of adipose fin by 12 to 13 scales, irregularly arranged. Adipose fin with convex dorsal margin and straight ventral margin. Lobes of caudal unequal, upper with rounded tip, and lower lobe longer and more pointed. Anal fin origin at level of end of dorsal fin base, its base 24.8- 27.9 (26.6 % SL); distal margin slightly falcate in adults and straight in juveniles. Pelvic fin not reaching origin of anal fin; distal margin of pelvic fin rounded. Distal margin of pectoral fin pointed and slightly falcate, not reaching pelvic insertion. Widths of scales on sides of body above lateral line and below row along dorsal fin greater than, or equal to, length of scale; anterior margins of these scales almost circular, somewhat irregular; circuli present on anterior two-thirds of scale; posterior field lacking circuli, possessing 2-3 centrally located, and almost parallel, striae. Dorsal-fin rays: unbranched 2*(23); branched 9*(23); total 11*(23). Anal-fin rays: unbranched 3(5), 4*(17); branched 26(6), 27(9), 28*(6), 29(1); total 29(1), 30(7), 31(9), 32*(4), 33(1). Pectoral-fin rays 12*(11), 13(10). Scales: predorsal 9(1), 11(4), 12*(16); lateral 41(6), 42(10), 43*(7), 44(1); pored lateral-line scales 43(2), 44(10), 45*(10), 46(1), 47(1); P -L scales 1(1), 2*(12), 3(11); rows above lateral line 7*(11), 8(10); rows below lateral line 4*(11), 5(10). Gill rakers: upper 5*(2), 6(19); lower 8(1), 9(16), 10*(4); total 14(2), 15*(16), 16(3). Vertebrae: precaudal 17(1), 18*(26); caudal 23(14), 24*(13); total 40(1), 41(13), 42*(13); dorsal-fin origin 11*(25), 12(2); anal-fin origin 17(1), 18*(26). Pigmentation in alcohol. Overall moderate dusky species in preservation, countershaded above and below lateral stripe. Dorsal profile of head dark, fully covered with fine melanophores homogeneously distributed. Anterior area of mouth dark. Nares not covered with pigment. Orbit with a black dorsal band. Infraorbitals and preopercle sparsely pigmented, more conspicuous at sutures. Opercle with star-like diffused spots, more evident in dorsal region. Lateral stripe originating just behind head, somewhat prominent in preservation; increasing in depth and intensity just posterior to dorsal fin origin, occupying three to four scale rows just behind midbody and ending in darker, oblong-shaped expansion just anterior to caudal fin. Centers of upper lateral scales pigmented densely. First 14 scales of lateral line canal outlined with pigment. Below lateral line, melanophores distributed along myosepta from just anterior to anus to midpoint of anal fin. Anal-fin base with a diffuse basal band formed by series of melanophores along pterygiophores. Dorsal, pectoral, and pelvic fins with melanophores outlining lower portion of fin rays. Adipose fin lacking melanophores. Both lobes of caudal fin densely covered by melanophores. A clear but diffuse area on anterobasal part of upper caudal lobe, not forming a well-defined ocellus. Distal margin of caudal fin area with a dark, almost black terminal band, especially on upper lobe. Coloration in life (Fig. 3c). Body usually grayish or metallic dorsolaterally, becoming silvery toward lateral and ventral flanks. A black lateral stripe extends from opercular opening to caudal fin base. Below this stripe there is a wider silvery stripe, limited dorsally by an iridescent metallic-yellow stripe. Head silver laterally. Iris yellow dorsally and silver ventrally. Cheek and opercular regions silvery. Dorsal part of head, snout and lower jaw dark. Dorsal fin slightly orange. Pectoral, pelvic and anal fins transparent. Adipose intense red. Caudal fin with dark distal margin, especially on upper lobe. Caudal-fin lobes with transparent areas near fin base diffuse and without well-formed ocelli. Upper lobe with red coloration in upper part of the diffuse area, the red extending posteriorly beyond this area, almost to end of the fin rays. Distribution. This new species is only known from the type locality, the Río Moquete, Anzoátegui State, Venezuela. The Río Moquete is a northern tributary of the Río Orinoco. Habitat. Bryconops magoi is known only from a morichal with fast moving waters over sandy bottoms. This species frequently is found in water from mid-depth to the surface, at the center of the main channel, where it schools with other characid species. Individuals feed at the surface and are attracted to allotochtonus material that falls into the water. Cursory examination shows that they feed on several groups of terrestrial insects. Etymology. The species-group name, magoi, is dedicated to the memory of Dr. Francisco Mago-Leccia, pioneer of modern ichthyological studies in Venezuela. Comparison with B. collettei. Bryconops magoi differs in body shape from B. collettei. The results of sheared principal components analysis and relative warp analysis show that all individuals of both species are discriminated by either the second sheared principal component (Fig. 6) or by the first relative warp. In both analyses all individuals of B. magoi fell at, or inside, the boundary of the 95% confidence ellipse, whereas three individuals of B. collettei fell just outside the 95% confidence ellipse, but with a morphology most different from B. magoi (Fig. 6). The first two eigenvectors of the PCA described 99.1% of the variance. The second sheared PC identified a contrasting suite of traits such that B. magoi has a longer snout and B. collettei has a longer anal fin base, a larger orbit, and a greater distance between the dorsal fins (Fig. 7). RWA produced identical results to the PCA. Even though individuals of B. collettei from the Río Iguapo have slightly longer snouts relative to other populations, there is no overlap in snout length between the species. For each of the other metric traits the differences between the species are statistically significant, but there is some overlap between the species.Published as part of Barry Chernoff & Antonio Machado-Allison, 2005, Bryconops magoi and Bryconops collettei (Characiformes: Characidae), two new freshwater fish species from Venezuela, with comments on B. caudomaculatus (Gunther)., pp. 1-23 in Zootaxa 1094 on pages 9-1
Pseudancistrus kwinti Willink, Mol & Chernoff, 2010, new species
No full textPseudancistrus kwinti, new species (Figs. 1–2, Table 1) Common name: Coppename Catfish Previous citations: Peckoltia sp. (new), Pseudancistrus barbatus, Berrenstein (2005) Peckoltia sp. 1, Pseudancistrus barbatus, Mol et al. (2006) Peckoltia sp., Willink & Sidlauskas (2006) Holotype: FMNH 116976, 94.3 mmSL, Suriname, Sipaliwini State, Coppename River at base of Sidonkroetoe-val rapids, Central Suriname Nature Reserve, 4 º 31 ’ 51 ”N, 56 º 30 ’ 56 ”W, J.H. Mol, B. Chernoff, P.W. Willink, and M. Cooperman, 9 March 2004. Paratypes: NZCS F 7066, 95.7 mm SL, Suriname, Sipaliwini State, Rapids of Midden Coppename River, Central Suriname Nature Reserve, 4 º 12 ’ 53 ”N, 56 º 35 ’ 54 ”W, J.H. Mol, B. Chernoff, P.W. Willink, and M. Cooperman, 2 March 2004; FMNH 116975, 43.9 mm SL, Suriname, Sipaliwini State, Coppename River at head of Tonckens-val rapids, Central Suriname Nature Reserve, 4 º 25 ’ 22 ”N, 56 º 31 ’ 34 ”W, J.H. Mol, B. Chernoff, P.W. Willink, and M. Cooperman, 23 February 2004. Diagnosis: Pseudancistrus kwinti can be diagnosed from all other described Pseudancistrus by the following combination of characters: dentary papillae absent (versus present in P. coquenani (Steindachner), P. o r i n o c o (Isbrücker et al.) (Fig. 3), P. pectegenitor Lujan et al., and P. yekuana Lujan et al.), mid-dorsal plate row complete (versus incomplete in P. genisetiger Fowler, P. papariae Fowler, and P. re u s Armbruster & Taphorn), coloration mottled or with bars (versus dark with white spots in P. barbatus (Valenciennes), P. corantijniensis de Chambrier & Montoya-Burgos, P. depressus (Günther), P. longispinis (Heitmans et al.), P. niger (Norman), P. nigrescens Eigenmann, and P. sidereus Ambruster or base of plates dark and edges pale in P. guentheri (Regan)), and hypertrophied odontodes along edge of snout (versus largely restricted to cheek plates in P. brevispinis (Heitmans et al.)). Description: Morphometric data in Table 1. Ventral surface flattened. Lateral profile of snout relatively straight at approximately 45 º angle. Profile curves from anterior of eye to supraoccipital, then increases slightly to dorsal-fin origin, the highest point on the body. Profile relatively straight and decreasing from dorsal-fin origin to caudal fin. Body relatively deep, dorsal-fin origin to pectoral-fin origin 30.3 –32.0% of standard length. Median lateral plates 24–25. Caudal peduncle plate rows 5. Plates covered by odontodes, but not keeled. Hypertrophied odontodes along posterior edge of plate. Cheek plates evertible to ~ 20 º from head. Abdomen without plates. No plates immediately around anus. Dorsal profile of snout rounded. Head width widest at evertible cheek plates. Body narrows from evertible cheek plates to caudal fin. Caudal peduncle compressed horizontally. Head relatively smooth. Anterior orbital rim slightly elevated. Low ridge from tip of snout to between nares. Eyes directed dorsolaterally. Orbit diameter 16.6–22.4 % of head length. Nares closer to eyes than to tip of snout. Hypertrophied odontodes along edge of snout, 15 (juvenile)– 67 (adult) on evertible cheek plates. Hypertrophied odontodes straight and directed laterally. All spines and rays on all fins with odontodes. Odontodes slightly larger on spines and unbranched rays. Pectoral fin I 6, reaching posterior end of pelvic-fin base when adpressed. Spine stout. First three branched rays extend distal of tip of spine. Distal margin convex. Pelvic fin i 5. Origin equal to second branched ray of dorsal fin, reaching posterior end of anal-fin base when adpressed. Unbranched ray hypertrophied and strengthed. First four branched rays extend distal of tip of unbranched ray. Distal margin convex. Anal fin i 4 (NZCS F 7066 anal fin i 5, but appears malformed). Origin equal to dorsal-fin termination, reaching middle of adipose fin when adpressed. First three branched rays extend distal of tip of unbranched ray. Distal margin convex. Dorsal fin Ii 7, with I and i fused. Origin anterior of pelvic fin, reaching just posterior end of adiposefin origin when adpressed. Distal margin convex. Adipose fin I, not reaching caudal fin. Membrane extends beyond distal tip of spine. Distal margin convex. Caudal fin i 14 i. Base at approximately 65 º angle, such that dorsalmost point of base is anterior of ventralmost point. Regardless of angle, caudal-fin ventral edge slightly longer than dorsal edge. Interior branched rays shorter than exterior unbranched rays, forming concave distal margin. Dorsal procurrent caudal-fin rays 5 and ventral procurrent caudal-fin rays 3 in FMNH 116975. Holotype Range Average SD Standard length (mm) 94.3 43.9–95.7 78.0 29.5 Mouth extending ¾ of distance across head. Premaxillary- and dentary-tooth rows gently curved. Premaxillary teeth 46–53. Dentary teeth 45–61. Teeth villiform, on stalks, bicuspid, with lateral cusp 50–85 % of the length of the medial cusp. Buccal papilla present. Dentary papillae absent. Lips not extending beyond margin of head. Posterior lobe longer than anterior lobe. Ventral surface of both lobes covered with papillae. Papillae fairly uniform in size, slightly larger towards mouth. Lip margins smooth except for slight unevenness caused by papillae. Posterior lip margin reaching level of opercular opening. Barbels short, not reaching halfway point to posterior margin of lip. Color in alcohol: Juvenile head brown with two faint pale bars (Fig. 1). First bar from ventralposterior corner of eye to cheek plate. Second bar from posterior margin of supraoccipital to base of pectoral spine. Body with alternating dark and pale bars. The four dark bars approximately twice as wide as pale bars (three or four plates wide versus one or two). Bars angled such that dorsal portion is anterior to ventral portion. First pale bar starts at dorsal-fin origin. Second pale bar starts near third branched ray of dorsal fin. Third pale bar starts at dorsal-fin termination. Fourth pale bar starts at adipose-fin origin. Ventral half of body slightly fainter than dorsal half. Dorsal fin with three alternating dark and pale bars confluent with the bars on the body. Distal margin pale. Adipose fin with one distal dark bar. Within dark bar, leading edge of fin and margin between fin and body are more heavily pigmented. Caudal fin with two wide alternating dark and pale bars. Caudal-fin base pale. Caudal-fin distal margin a wide dark bar with a very narrow hyaline edge. Pectoral fin brown; less pigmented at base and distal margin, forming two faint pale bars and dark central bar. Pelvic fin brown; less pigmented at base and distal margin, forming two faint pale bars and dark central bar, each confluent with bars on body. Anal fin less pigmented at base and distal margin, forming two faint pale bars and dark central bar, each confluent with bars on body. Barbels and posterior margin of lip pigmented. Oral disk pale. Abdomen pale with moderate amount of pigmentation along sides between pectoral and pelvic fins. Ventral plates pigmented in the same alternating bar pattern as lateral plates. Adult head and body brown, with some pale mottling (Fig. 2). Juvenile pale bands faded with some remnants present, especially at junction of dorsal and mid-dorsal plate rows. Ventral half of body slightly fainter than dorsal half. Dorsal fin with four alternating pale and dark bars. Tip of unbranched ray and first branched ray pale, but tips of all other rays dark. Adipose fin spine dark except for pale tip. Distal adipose membrane adjacent to spine pale, otherwise dark. Caudal fin between base and fork with three to four alternating pale and dark bars. Caudal-fin base pale. Bars partially interconnected in holotype (Fig. 2). Caudal-fin tips with additional paledark-pale sequence. Pectoral fin brown, slightly mottled. Pelvic fin with three alternating dark and pale bars. Pelvic-fin base dark. Proximal half of anal fin dark, distal half pale. Barbels and posterior margin of lip pigmented. Oral disk pale. Abdomen pale with moderate amount of pigmentation along sides between pectoral and pelvic fins. Ventral plates uniformly pale with slight pigmentation. Sexual dimorphism: In most species of Pseudancistrus, the hypertrophied odontodes along the snout are relatively longer in males than in females (Armbruster, 2004). This appears to be the case in P. k w i n t i, although the sample size is small. Range: Pseudancistrus kwinti is only known from the Coppename River drainage, Sipaliwini, Suriname (Fig. 4). These localities are within the Central Suriname Nature Reserve. Habitat: Pseudancistrus kwinti was collected in rapids (Fig. 5). Substrate was rubble, boulders, and cracked bedrock with patches of the aquatic plant Podostemaceae. Clear water. Swift current. Etymology: The species-group name, kwinti, refers to the Kwinti people that live along the Coppename River and traditionally fish the area in which the new species was discovered (Hoogbergen, 1992). The gender of Pseudancistrus is masculine. The species-group name is treated as a noun in apposition.Published as part of Willink, Philip W., Mol, Jan H. & Chernoff, Barry, 2010, A new species of suckermouth armored catfish, Pseudancistrus kwinti (Siluriformes: Loricariidae) from the Coppename River drainage, Central Suriname Nature Reserve, Suriname, pp. 40-48 in Zootaxa 2332 on pages 41-46, DOI: 10.5281/zenodo.19312
Bryconops (Bryconops)
No full textComparisons within the subgenus Bryconops Bryconops collettei and B. magoi possess the derived characters of the subgenus Bryconops (Chernoff and Machado-Allison, 1999), which include reduction in the ossification and denticulation of the gill rakers, despite being large fishes, and lack of maxillary teeth, with at most (and rarely) only a single, small conical tooth on one side. The subgenus Bryconops contains six species. B. alburnoides differs from the other five species by being much larger, reaching almost 200mm SL, and by having more lateral scales and branched anal-fin rays (see key). Importantly, B. alburnoides lacks an ocellus or clear areas containing coloration on the caudal fin. B. alburnoides often has pale to bright yellow suffused among the caudal fin rays, but this color is not concentrated within a circumscribed area on either fin lobe. Furthermore, the dorsal and adipose fins of B. alburnoides are dusky to pale yellow, never red. The remaining five species in this subgenus comprise the B. caudomaculatus species complex. We refer the five species to this informal group because of their phenotypic similarity and because they have all been referred to, or synonymized with B. caudomaculatus at some point in their history. The following characteristics are common to the complex: (i) the dorsal fin has a crescent of red (a potential synapomorphy), (ii) the adipose fin is entirely red, and (iii) the caudal fin has at least a clear circumscribed area on the upper lobe that is either entirely, or partially, filled with red color. This ocellus is either well formed or irregular (Fig. 2). B. magoi and B. collettei differ from the other members by having the dorsal-fin ocellus only partially filled with red color (Fig. 3), the overall form of which appears as a streak or narrow ellipse; the color becomes diffuse and extends beyond the ocellus among the upper caudal-fin rays. This condition in the new species is independent of sex or state of maturity, since even specimens as small as 35 mm SL show the diffuse coloration pattern, though the color may be slightly less intense. Both B. disruptus and B. durbini have very few pored lateral scales (36) that extend nearly to or beyond the end of the hypural plate.Published as part of Barry Chernoff & Antonio Machado-Allison, 2005, Bryconops magoi and Bryconops collettei (Characiformes: Characidae), two new freshwater fish species from Venezuela, with comments on B. caudomaculatus (Gunther)., pp. 1-23 in Zootaxa 1094 on pages 5-
Two new miniature silverside fishes of the genus Membras Bonaparte (Atheriniformes, Atherinopsidae) from the Tropical North Atlantic Ocean
No full textChernoff, Barry, Machado-Allison, Antonio, Escobedo, Jennifer, Freiburger, Michael, Henderson, Elijah, Hennessy, Andrew, Kohn, Grace, Neri, Nola, Parikh, Aashni, Scobell, Sophie, Silverstone, Benjamin, Young, Emily (2020): Two new miniature silverside fishes of the genus Membras Bonaparte (Atheriniformes, Atherinopsidae) from the Tropical North Atlantic Ocean. Zootaxa 4852 (2): 191-202, DOI: 10.11646/zootaxa.4852.2.
FIGURE 3. A in Two new miniature silverside fishes of the genus Membras Bonaparte (Atheriniformes, Atherinopsidae) from the Tropical North Atlantic Ocean
No full textFIGURE 3. A. Membras pygmaea sp. nov., holotype, FMNH 117282, 40.2 mm SL. B. Membras procera sp. nov., holotype, ANSP 153427, 36.6 mm SL.Published as part of Chernoff, Barry, Machado-Allison, Antonio, Escobedo, Jennifer, Freiburger, Michael, Henderson, Elijah, Hennessy, Andrew, Kohn, Grace, Neri, Nola, Parikh, Aashni, Scobell, Sophie, Silverstone, Benjamin & Young, Emily, 2020, Two new miniature silverside fishes of the genus Membras Bonaparte (Atheriniformes, Atherinopsidae) from the Tropical North Atlantic Ocean, pp. 191-202 in Zootaxa 4852 (2) on page 195, DOI: 10.11646/zootaxa.4852.2.4, http://zenodo.org/record/440979
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