2,182 research outputs found
Lepadella hanneloreae Luo & Segers 2020, n. sp.
No full text<i>Lepadella hanneloreae</i> n. sp. <p>Figures 5 a–c, I-4</p> <p> <b>Type locality.</b> Lohulu River near Bomane, DR Congo 24 May 2010 (KM49, KM48); a few specimens from Yangambi primary forest, DR Congo, 11 June 2012 (Y25). Numerous additional specimens in the samples from the type locality.</p> <p> <b>Material examined.</b> Holotype: female specimen in permanent slide, deposited in RBINS (RIR.292); Paratypes: seven permanent slides containing one female specimen each, deposited in RBINS; five permanent slides containing two female specimens each, deposited in RBINS (RIR.293 to RIR.304), one permanent slide containing three female specimens, deposited in CSB-UK.</p> <p> <b>Differential diagnosis.</b> <i>Lepadella hanneloreae</i> <b>n. sp.</b> is strikingly similar to <i>L. amazonica</i> Segers, 1993 (in Segers <i>et al</i>. 1993b). The two differ by the dorsal carinae on the lorica: in <i>L. hanneloreae</i> <b>n. sp.</b> there is one pair of middorsal and one pair of lateral carinae, whereas in <i>L. amazonica</i> there are two pairs of closely adjacent lateral carinae. Furthermore, the new species is probably related to <i>L. berzinsi</i> Segers, 1993, but the latter has three pairs of more pronounced carinae situated at regular distances from each other.</p> <p> <b>Description.</b> Parthenogenetic female (male unknown): Lorica elongate, roughly egg-shaped, width about two thirds of length. Ventral lorica flat, dorsal domed, lorica about twice as wide as high. Head aperture ventrally a deep V-shaped sinus, dorsally semi-circular in anterior view, straight in ventral view, with stippled collar. Dorsal lorica with two pairs of longitudinal carinae: one median pair, fused in the distal third of the lorica, one lateral pair running from behind the collar to approximately level of the apertures to the dorsal antennas. Lateral edges of lorica smooth, evenly curved, posterior edge nearly straight or with a shallow median notch. Apertures to the lateral antennas situated at the level of the anterior margin of the foot aperture, arranged symmetrically about medially from the fused median carinas to the lateral margin of the lorica. Foot aperture elongate, lateral margins nearly parallel. Foot with three distinct pseudosegments, the distal one about twice as long as the second, bearing a dorsal sensory groove near its basis. Two equal toes, these evenly tapering to distally.</p> <p> <b>Measurements</b> (n=10). Lorica length: 91–106 (100), width: 60–70 (67); head aperture width: 23–37 (29), head aperture depth dorsally: 7–14 (10), ventrally: 19–24 (21); foot aperture width: 18–20 (19), length: 23–33 (27), toe length: 22–29 (25).</p> <p> <b>Etymology.</b> The specific name is as a noun in the genitive case, after Mrs Hannelore Segers, daughter of the second author of this paper.</p>Published as part of <i>Luo, Yongting & Segers, Hendrik, 2020, Eight new Lepadellidae (Rotifera, Monogononta) from the Congo bring to level endemism in Africa's rotifers, pp. 371-387 in Zootaxa 4731 (3)</i> on pages 374-376, DOI: 10.11646/zootaxa.4731.3.6, <a href="http://zenodo.org/record/3653632">http://zenodo.org/record/3653632</a>
Lacinularoides Meksuwan, Pholpunthin & Segers, 2011, new genus
No full textGenus Lacinularoides, new genus (Figs 4–5) Type species. Lacinularoides coloniensis (Colledge, 1918), new combination Differential diagnosis. The new genus is characterized by having a corona consisting of five or seven lobes and by the absence of an oviferon (egg-carrying organ). Although the size of the animals and their corona shape both remind one of Pentatrocha Segers & Shiel, 2008, they are separated from this genus by the absence of an oviferon and presence of obvious gelatinous matrix formation, and by the coronal lobes being much smaller than in Pentatrocha. While Pentatrocha has never been observed other than solitary, the single constituent species of Lacinularoides is colonial. By lacking an oviferon, which we consider a synapomorphic feature for a [Pentatrocha, Sinantherina Bory de St. Vincent, 1826] clade, and by having a corona exhibiting distinct lobes, we surmise that the taxon is closest to Octotrocha Thorpe, 1893, which has an even more intricately lobed corona. We further believe the new genus is close to Lacinularia Schweigger, 1820, which has a very similar morphology but which has a corona that has, at the most, a ventral concavity giving it a heart-shaped appearance (see Table 4). Description. Mature female large, foot long, foot peduncle tiny or almost invisible. Corona large, with five prominent and two small lobes: a large pair of ventral lobes separated by a deep ventral sinus; a pair of small or, occasionally, indistinct lateral lobes and three dorsal lobes. Single species known to date, living sessile in small to large colonies, occasionally solitary (first specimen of newly established colony?), inhabiting a clear to light-brown coloured gelatinous case. Trophi malleoramate. Etymology. The name Lacinularoides (gender: masculine) is derived from that of its relative, Lacinularia. Redescription of Lacinularoides coloniensis (Colledge, 1918), n. comb. Animal large, transparent, internal organs obvious. Trunk fusiform, tapers gradually into tapering foot, neck region slightly curved dorsally when animal expands the corona. Foot long, with abundant foot glands along upper half part, peduncle tiny. Extended corona large, five- to seven-lobed, consisting of a conspicuous pair of ventral, a pair of occasionally indistinct lateral, and three dorsal lobes. The lobes of the ventral pair are rather round, held perpendicular to the longitudinal axis of the body; the lateral lobes are relatively small and appear to be made up by an S-shaped curve of the lateral corona margins. The dorso-lateral lobes are round but with rather straight latero-dorsal sections, tilted to ca. 60 degrees versus the body axis and slightly bent to ventrad; the middorsal lobe relatively small but distinct, slightly triangular. Ventral lobes separated by a deep, U-shaped sinus, separation of dorsal and especially lateral lobes shallow. Dorsal gap tiny; apical field surface bulged by the large mastax. Small projection bearing the dorsal antenna under the dorsal corona lobe. Lateral antenna on minute conical papillae. Gelatinous matrix clear to light-brown, containing the eggs, if any. Male: see Colledge (1918). Trophi nearly symmetrical, malleoramate; unci teeth strongly differentiated. Proximal unci teeth on both sides with three strong teeth, the first smallest in size, the first tooth on the left side bigger than on the right; distal unci teeth of both sides weak, relatively few (2–3). Mature females total length ca. 1,300 µm. Trunk length ca. 460 µm, width ca. 130 µm. Foot length ca. 820 µm. Corona height ca. 380 µm, width ca. 360 µm. Parthenogenetic egg size ca. 160 x 100 µm. Remarks. Although we recognize this taxon as representing the genus newly described herein (with the caveat that the diagnosis of genera in Flosculariidae is in urgent need of revision; see comment in Segers & Shiel 2008), the species appears to have been recorded repeatedly before. We accept that the present material is conspecific with the animal described in good detail in 1918 by W. R. Colledge, as Melicerta coloniensis, from a “pool at Goodna, Qld” (Colledge, 1925) Australia. The taxon had not been recorded ever since and it appears to have been overlooked. The reason for this may be historical, and lay in confusion between L. coloniensis and Octotrocha speciosa. We know from the study of W.T. Edmondson’s notebooks that this author, an authority on sessile rotifers, considered both O. speciosa and L. coloniensis as possible identity of animals before him. We now know that the two can relatively easily be distinguished, even in contracted state, by their trophi morphology, a feature that at that time was hardly considered in identification of sessile rotifers: the differentiation in development of the unci teeth is noticeably stronger in L. coloniensis than in O. speciosa (compare Figs 5 a–c with Fig. 7 in Segers et al., 2011). Based on a re-evaluation of published drawings and photographs of trophi morphology, Segers et al. (2011) reevaluated previously published and (partly) illustrated records of Octotrocha speciosa Thorpe, 1893 by Edmondson (1959), Koste (1974, 1978, 1989), Sarma & Elias-Gutierrez (1998), and Segers & Shiel (2008) as being misidentified, and with the information we now have available we suggest that these records all pertain to L. coloniensis. This would imply that, whereas both species co-occur in Southeast Asia and China, L. coloniensis is much more widespread and may be the only one of the two that occurs in Australia and the Americas. This precludes direct comparison of the two by zoologists working outside the area of O. speciosa, including W.T. Edmondson. Based on the present considerations, we now are quite sure that the glass model of a small colony of sessile rotifers identified as O. speciosa Thorpe, on exhibit in the American Museum of Natural History (see Fig. 1.1. in Wallace et al. 2006) and whose identity had already been questioned by Segers & Shiel (2008), represents L. coloniensis. Similarly, as our observations confirm Octotrocha speciosa as a solitary animal, we assume that the autorecruitive nature of colony formation of O. speciosa as reported by Wallace et al. (2006) refers to L. coloniensis. Indeed, a photograph kindly supplied by R.L. Wallace of the animals he studied indeed appears to depict L. coloniensis.Published as part of Meksuwan, Phuripong, Pholpunthin, Pornsilp & Segers, Hendrik, 2011, Diversity of sessile rotifers (Gnesiotrocha, Monogononta, Rotifera) in Thale Noi Lake, Thailand, pp. 1-18 in Zootaxa 2997 on pages 8-12, DOI: 10.5281/zenodo.20799
Lepadella jingruae Luo & Segers 2020, n. sp.
No full textLepadella jingruae n. sp. Figures 6 a–c, I-5 Type locality. Lohulu River near Bomane, DR Congo 24 May 2010 (KM48, KM49). Material examined. Holotype: one female specimen in permanent slide, deposited in RBINS (RIR.305); Paratypes: six permanent slides containing one female specimen each, deposited in RBINS (RIR.306 to RIR.311), one permanent slides containing one female specimen and one permanent slide containing two female specimens in CSB-UK; one permanent slide containing two female specimens, deposited in SHNU. Differential diagnosis. The relatively flat lorica of L. jingruae n. sp. places the species in the vicinity of L. ovalis (Müller, 1786) and L. eurysterna Myers, 1942. The new species is diagnosed from both by the remarkable protruding projections laterally of the head aperture, and further from L. ovalis by its smaller size and posteriorly rounded lorica (relatively large and with a sharply set-of posterior concavity in L. ovalis). Lepadella jingruae n. sp. can easily be distinguished from species of the L. patella— complex, including the similarly rounded L. discoidea Segers, 1993 by its flat lorica and the protruding lateral projections of the head aperture. Differential diagnosis. Parthenogenetic female (male unknown): Lorica rounded, about as wide as long. Ventral lorica flat, dorsally with a central dome, lateral parts strongly flattened, lorica about thrice as wide as high. Head aperture ventrally a deep V-shaped sinus, dorsally semi-circular in anterior view, broadly U-shaped in ventral view, with weak collar. Anterior of lorica protruding into a pair of well-developed, sharp projections. Lateral margins of lorica smooth, evenly curved, posterior edge convex. Dorsal lorica smooth, without markings. Apertures to the lateral antennas situated slightly posterior the level of the anterior margin of the foot aperture, arranged symmetrically about medially from median axis to the lateral margin of the lorica. Foot aperture elongate, lateral margins diverging to posteriorly. Foot with three distinct pseudosegments, the distal one about twice as long as the second, bearing a dorsal sensory groove near its basis. A pair of equal-sized toes present, these almost parallel-sided basally, more strongly tapering from about midway to distally. Measurements (n=10). Lorica length: 100–110 (106), width: 90–101 (93); head aperture width: 25–31 (28), depth dorsally: 15–21 (18), depth ventrally: 24–28 (25), foot aperture width: 15–19 (18), length: 26–31 (28), toe length: 26–29 (29). Etymology. The specific name is as a noun in the genitive case, after Miss Jingru Zhu, daughter of the first author of this paper.Published as part of Luo, Yongting & Segers, Hendrik, 2020, Eight new Lepadellidae (Rotifera, Monogononta) from the Congo bring to level endemism in Africa's rotifers, pp. 371-387 in Zootaxa 4731 (3) on page 376, DOI: 10.11646/zootaxa.4731.3.6, http://zenodo.org/record/365363
Scientific thinking in kindergarten
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170681.pdf (Publisher’s version ) (Open Access)Radboud University, 07 juni 2017Promotores : Verhoeven, L.T.W., Segers, P.C.J.167 p
The role of linguistic diversity in early reading comprehension
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214843.pdf (Publisher’s version ) (Open Access)Radboud University, 14 januari 2020Promotores : Verhoeven, L.T.W., Segers, P.C.J.175 p
Lepadella yangambi Luo & Segers 2020, n. sp.
No full text<i>Lepadella yangambi</i> n. sp. <p>Figures 8 a–d, I-8</p> <p> <b>Type locality.</b> Yangambi primary forest, DR Congo, 11 June 2012 (Y27).</p> <p> <b>Material examined.</b> Holotype: One female specimen in permanent slide, deposited in RBINS (RIR.321); Paratypes: seven permanent slides containing one female specimen each, and three permanent slides containing two female specimens each, deposited in RBINS (RIR.322 to RIR.331); two permanent slides containing three female specimens each, CSB-UK; one permanent slide containing five female specimens, deposited in SHNU; numerous additional specimens in the sample from the type locality.</p> <p> <b>Differential diagnosis.</b> <i>Lepadella yangambi</i> <b>n. sp.</b> can be confused with <i>Lepadella bidentata</i> Voronkov, 1913 and <i>L. dactyliseta</i> (Stenroos, 1898). While the posterior spines are clearly set off from the lorica in <i>L. yangambi</i> <b>n. sp.</b> and formed as extensions of the lorica in the other taxa, the deeply invaginated dorsal head aperture margin and blunt sublongitudinal ridges on the dorsal lorica are unique to <i>L. yangambi</i> <b>n. sp.</b> Finally, the new species has a much higher lorica than <i>L. biloba</i> Hauer, 1958.</p> <p> <b>Differential diagnosis.</b> Parthenogenetic female (male unknown): Lorica elongate, elliptical, width about two thirds of length. Ventral lorica relatively flat, dorsally strongly domed, lorica less than twice as wide as high. Dorsal lorica ornamented by a pair of sublongitudinal, sublateral, blunt ridges starting near the head aperture, and running to near the openings of the dorsal antennas. Head aperture ventrally a deep U- or V-shaped sinus, dorsally semi-circular in anterior view, broadly U-shaped in ventral view, no collar. Lateral edges of lorica smooth, evenly curved, posterior edge convex. Apertures to the lateral antennas situated at the level of the first foot pseudosegment in contracted specimens, arranged symmetrically about medially from the longitudinal symmetry axis to the lateral margins of the lorica. Foot aperture elongate, broadest medially, lateral margins converging to both anteriorly and posteriorly. Foot with three distinct pseudosegments, the distal one slightly longer than the second, bearing a dorsal sensory groove near its basis. Two equal toes, these evenly tapering to distally.</p> <p> <b>Measurements</b> (n=10). Lorica length: 75–82 (77), lorica width: 58–75 (61), head aperture width: 23–28 (25), depth dorsally: 5–12 (7), ventrally: 15–20 (18), foot aperture width: 12–18 (14), length: 18–19 (18), toe length: 17–21 (19).</p> <p> <b>Etymology.</b> This specific name is a noun in apposition, derived from the name of its type locality, Yangambi primary forest.</p>Published as part of <i>Luo, Yongting & Segers, Hendrik, 2020, Eight new Lepadellidae (Rotifera, Monogononta) from the Congo bring to level endemism in Africa's rotifers, pp. 371-387 in Zootaxa 4731 (3)</i> on page 378, DOI: 10.11646/zootaxa.4731.3.6, <a href="http://zenodo.org/record/3653632">http://zenodo.org/record/3653632</a>
Children's digital text comprehension
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138657.pdf (Publisher’s version ) (Open Access)Radboud Universiteit Nijmegen, 16 maart 2015Promotor : Verhoeven, L.T.W. Co-promotor : Segers, P.C.J.171 p
Enhancing word reading fluency in beginning readers
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150852.pdf (Publisher’s version ) (Open Access)Radboud Universiteit Nijmegen, 18 januari 2016Promotor : Verhoeven, L.T.W. Co-promotor : Segers, P.C.J.143 p
Lepadella wilungulai Luo & Segers 2020
No full text<i>Lepadella wilungulai</i> n. sp <p>Figures 9 a–c, I-6</p> <p> <b>Type locality.</b> Lulu River near Basoko, DR Congo 21 May 2010 (KM27).</p> <p> <b>Material examined.</b> Holotype: one female specimen in permanent slide, deposited in RBINS (RIR.320).</p> <p> <b>Differential diagnosis.</b> The three exceptionally well-developed dorsal carinae of <i>L. wilungulai</i> <b>n. sp.</b> distinguish the species unequivocally from all congeners. The only species with which the animal might be compared is <i>L. donneri</i> Koste, 1972 which has very similar lateral carinae but which lacks the dorsal carina and which has a more rounded lorica. A third, unnamed Neotropical relative recorded by Koste & Böttger (1992) as “ <i>Lepadella quinquecostata</i> nov. forma?” and by José de Paggi (2001) as <i>L. quinquecostata</i> also has extraordinarily developed carinae, but this animal has five, less developed and differently situated carinae, is larger, and has a differently shaped lorica.</p> <p> <b>Differential diagnosis.</b> Parthenogenetic female (male unknown): Lorica elongate, roughly egg-shaped, width about two thirds of length. Ventral lorica nearly flat, dorsal domed, lorica about twice as wide as high. Head aperture ventrally a deep U-shaped sinus, dorsally semi-circular in anterior view, a broad U-shaped sinus in ventral view, with collar. Dorsal lorica with three longitudinal carinae: one median, and a pair of lateral carinas running from the anterior tips of the lorica to just anterior of the apertures to the dorsal antennas. Dorsal carina extremely high and narrow. Lateral edges of lorica smooth, evenly curved, posterior edge with a minute convex projection as extension of the dorsal carina. Apertures to the lateral antennas situated at the level of the anterior margin of the foot aperture, arranged symmetrically about medially from the middorsal carina to the lateral margin of the lorica. Foot aperture elongate, lateral margins nearly parallel. Foot with three distinct pseudosegments, the distal one about thrice as long as the second, bearing a dorsal sensory groove near its basis. A pair of equal-sized toes present, these almost parallel-sided proximally, more strongly tapering from about midway to distally.</p> <p> <b>Measurements</b> (n=1). Lorica length: 117, width: 86; Head aperture width: 24, head aperture depth dorsally: 8, ventrally: 19, Foot aperture width: 16, length: 30, toe length: 33.</p> <p> <b>Etymology.</b> The specific name is as a noun in the genitive case, dedicated to Dr Father Cosma Wilungula, Executive director of the Institut Congolais pour la Conservation de la Nature, in recognition of his contribution to nature conservation in the Democratic Republic of Congo.</p> <p> <b>Remark.</b> We acknowledge that describing and naming a new rotifer species based on a single specimen is a practice frowned upon, for good reasons, by numerous authorities including, e.g., Ruttner-Kolisko (1989) and Koste & Shiel (1989). However, the unique features of the holotype, the outstandingly easy diagnosis and the potential biogeographical relevance of the animal convince us to exceptionally proceed with the description and establishment of a new name for the single specimen discovered.</p>Published as part of <i>Luo, Yongting & Segers, Hendrik, 2020, Eight new Lepadellidae (Rotifera, Monogononta) from the Congo bring to level endemism in Africa's rotifers, pp. 371-387 in Zootaxa 4731 (3)</i> on page 377, DOI: 10.11646/zootaxa.4731.3.6, <a href="http://zenodo.org/record/3653632">http://zenodo.org/record/3653632</a>
Ptygura thalenoiensis Meksuwan, Pholpunthin & Segers, 2011, new species
No full text<i>Ptygura thalenoiensis</i> new species <p>(Figs 6–7)</p> <p> Synonym: <i>Ptygura</i> sp. near <i>linguata</i> Edmondson, 1939 <i>after</i> Segers <i>et al</i>., 2011 (Figs 9 –12)</p> <p> <b>Type material.</b> Holotype female (PSUZC-PK5PM001-01) was deposited in Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Songkhla, Thailand; two paratype females deposited in RBINS, BRUSSELS, GI 31863 RIR 202-203.</p> <p> <b>Type locality.</b> Thale Noi Lake, Phatthalung province, Thailand: 7o 45’ 44’’ N to 7o 48’ 26’’ N and longitude 100o 7’ 31’’ E to 100o 11’ 12’’ E, June 2009 through April 2010.</p> <p> <b>Differential diagnosis.</b> The new species belongs to a group of congeners that are diagnosed by having elongate lateral antenna. Amongst those, <i>P. thalenoiensis</i> <b>n. sp.</b> is distinguished by the presence of a pair of apical hooks in addition to a tongue-shaped projection in between those, and of an autapomorphic ciliated projection in its mouth region.</p> <p> <b>Description.</b> Body well separated from the elongate, retractible foot, terminating in a medium to long peduncle. Corona elliptic, twice as wide as trunk; dorsal gap minute; corona supported by relatively strong rods. Buccal area with distinct short and cylindrical projection bearing a group of elongate cilia terminally. Neck region distinct, with two sharp dorsal hooks lateral to a tongue-shaped projection, this projection protruding beyond, but less rigid than the hooks. Lateral antenna long and slender. Tube gelatinous, containing fine perpendicular lines of material radiating from the inside of the tube. Fine layers radiated from inner sheath; light to medium brown; inner sheath obvious, quite parallel along tube to. Male unkown.</p> <p>Trophi nearly symmetrical, malleoramate. Unci left and right 17 teeth, these weakly differentiated into a proximal group containing 3 slightly stronger teeth and a distal group of weaker teeth (3–4 teeth); second tooth in the left group of proximal teeth small. Teeth in the distal group interdigitating with rami scleropilli (visible most in the left group). Fulcrum short, with a weakly developed basal plate.</p> <p> <b>Measurements.</b> Females total length ca. 700 µm. Trunk length ca. 150–230 µm, width ca. 40–50 µm. Foot length ca. 200–450 µm. Foot stalk length ca. 15–60 µm. Corona height ca. 90 µm, width ca. 140 µm, width/height ratio ca. 1.6. Lateral antenna length ca. 80 µm.</p> <p> <b>Etymology.</b> The species name <i>thalenoiensis</i> is an adjective, derived from the type locality of the species.</p> <p> <b>Distribution.</b> In addition to the type locality, the new species is known from Cambodia (sub. <i>Ptygura</i> cf. <i>linguata,</i> Segers <i>et al.,</i> 2011). Apparently, it is endemic to Southeast Asia.</p>Published as part of <i>Meksuwan, Phuripong, Pholpunthin, Pornsilp & Segers, Hendrik, 2011, Diversity of sessile rotifers (Gnesiotrocha, Monogononta, Rotifera) in Thale Noi Lake, Thailand, pp. 1-18 in Zootaxa 2997</i> on page 12, DOI: <a href="http://zenodo.org/record/207999">10.5281/zenodo.207999</a>
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