Testing for nematode–granulometry relationships

The majority of studies have advocated that diversity of marine nematodes increases with increasing sediment grain size, although the opposite trend has also been suggested. The controversy is partially caused by not taking into account the effect of density on patterns of diversity and by analyzing datasets from different environments. The present study investigated nematode assemblages from sediments varying from very fine sand (mean grain size of 0.12 mm) to very coarse sand (1 mm) in shallow sublittoral marine environments. Contrary to previous studies, species richness was constant along the granulometric spectrum, despite significant changes in composition. The dominant genera were separated into five groups according to their optimum distribution and there was little overlap between these groups. Concepts from the niche theory explain to some extent the observed patterns. For instance, some of the coexisting genera were from different feeding types

The state of the art of Xyalidae (Nematoda, Monhysterida) with reference to the Brazilian records

In the current study we provide a reviewed list of valid genera and species of Xyalidae, a widespread family of mostly marine free-living nematodes. Comments are added about the historic background and taxonomic situation of the family, all valid genera and, when necessary, diagnostic characters are given. Additionally, information about distribution and geographical location of species recorded along the Brazilian coast is provided. Our review recognized 46 valid genera, 450 valid species and 73 descriptions without enough morphological information for identification (species inquerendae). Nearly 80 % of the species inquerendae belong to Daptonema and Theristus. To avoid homonymies, two Daptonema species were renamed, Daptonema biwaensis (Tsalolikhin, 2002) new name (former Mongolotheristus timoshkini) and Daptonema vietnamensis (Gagarin and Thu, 2008) new name (former D. curvatum sensu Gagarin and Thu, 2008). Cenolaimus sapeloensis is transferred to Xyala sapeloensis comb. nov. Along the Brazilian coast 28 genera and 41 species have been recorded. The species Elzalia floresi, Metadesmolaimus tersus, Paramonohystera stricta, Pseudosteineria scopae, Rhynchonema cemae, R. veronicae, Steineria ericia, S. marcorum, S. pavo, S. tripartita, Theristus acribus, T. flevensis, T. macroflevensis, T. pertenuis, T. stranus, Trichotheristus heterus, T. setosus and Zygonemella striata have the Brazilian coast as the type locality. Among all species, three occurred across three geographic regions, while the large majority was restricted to one. Xyalidae is typically encountered in oceanic sandy beaches, with only the species belonging to Daptonema, Theristus, Trichotheristus and Zygonemella being recorded in estuarine sediments. This observation suggests that the colonization of inland waters occurred multiple times along the evolutionary history

FIGURE 3 in On the taxonomy of Apistobranchus species (Polychaeta: Apistobranchidae) from the Antarctic

FIGURE 3. Apistobranchus glacierae (Martel Inlet). Scanning electron micrographs. Adult (A–H). Juvenile (I). A. Anterior end, ventral view, ciliated prostomium and ventral band, mouth, palps. B. Dorsal view, nuchal organ, only interramal cirri on setiger 1. C. Bottle-shaped notopodium, post-setal lamelae from setiger 4. D. Dorsal view, ciliated interramal cirri and notopodium, anterior neurosetae. E–F. Splintered limbate setae. G. Limbate and capillary setae. H. Dorsal view, post-setal lamelae of setigers 5–8. I. Difference in post-setal lamelae morphology. Abbreviations: anc, anterior neurosetae; cvb, ciliated ventral band; irc, interramal cirri; mth, mouth; neu, neuropodium; ntp, notopodium; nuc, nuchal organ; palp, palp; pros, prostomium; psl, post-setal lamellae. Scales: A, C, I, 100 µm; B, D, G, H, 30 µm; E, F, 10 µm.Published as part of <i>Varella Petti, Mồnica A., Nonato, Edmundo F., Bromberg, Sandra, Gheller, Paula F., Paiva, Paulo Cesar & Corbisier, N., 2007, On the taxonomy of Apistobranchus species (Polychaeta: Apistobranchidae) from the Antarctic, pp. 51-59 in Zootaxa 1440 (1)</i> on page 55, DOI: 10.11646/zootaxa.1440.1.4, <a href="http://zenodo.org/record/10087931">http://zenodo.org/record/10087931</a&gt

On the taxonomy of Apistobranchus species (Polychaeta: Apistobranchidae) from the Antarctic

Varella Petti, Mồnica A., Nonato, Edmundo F., Bromberg, Sandra, Gheller, Paula F., Paiva, Paulo Cesar, Corbisier, N. (2007): On the taxonomy of Apistobranchus species (Polychaeta: Apistobranchidae) from the Antarctic. Zootaxa 1440 (1): 51-59, DOI: 10.11646/zootaxa.1440.1.

Hypodontolaiminae De Coninck 1965

Sub-family Hypodontolaiminae <p> Diagnosis (after Tchesunov, 2014): Cuticle homo- or heterogenous with or without the presence of lateral differentiation of larger dots. Six outer labial papillae and four cephalic setae in two separate circles (except in <i>Megodontolaimus coxbazari</i>). Amphidial fovea distinct or rather obscure, transverse flattened oval, generally located between the four cephalic setae. Stoma funnel shaped, armed with hollow teeth; the larger dorsal tooth maybe opposed by two smaller ventrosublateral teeth, denticles may be present; anterior part of pharynx often with prominent dorsal muscular swelling. Males with cup-like precloacal supplements, rarely absent. Mostly marine but some genera have representatives in freshwater or brackish water (see more detailed in each genus).</p>Published as part of <i>Venekey, Virag, Gheller, Paula F., Kandratavicius, Noelia, Cunha, Beatriz Pereira, Vilas-Boas, Ana Carolina, Fonseca, Gustavo & Maria, Tatiana F., 2019, The state of the art of Chromadoridae (Nematoda, Chromadorida): a historical review, diagnoses and comments about valid and dubious genera and a list of valid species, pp. 1-67 in Zootaxa 4578 (1)</i> on page 33, DOI: 10.11646/zootaxa.4578.1.1, <a href="http://zenodo.org/record/2637441">http://zenodo.org/record/2637441</a&gt

Spilipherinae Filipjev 1918

Subfamily Spilipherinae <p>Diagnosis (after Tchesunov, 2014): Cuticle homo- or heterogenous with or without the presence of lateral differentiation of larger dots. Six outer labial setae and four cephalic setae usually in a single circle. Amphidial fovea situated laterally on the head, spiral, i.e., either cryptospiral with a circular outline or a single-loop spiral with at most 1.5 turns. Buccal cavity with three or more solid teeth with or without apophyses. Pharynx with subdivided end bulb. Males with precloacal supplements setose or absent. Tail conical or elongate. All genera in this subfamily are marine, with no records so far in freshwaters.</p>Published as part of <i>Venekey, Virag, Gheller, Paula F., Kandratavicius, Noelia, Cunha, Beatriz Pereira, Vilas-Boas, Ana Carolina, Fonseca, Gustavo & Maria, Tatiana F., 2019, The state of the art of Chromadoridae (Nematoda, Chromadorida): a historical review, diagnoses and comments about valid and dubious genera and a list of valid species, pp. 1-67 in Zootaxa 4578 (1)</i> on page 48, DOI: 10.11646/zootaxa.4578.1.1, <a href="http://zenodo.org/record/2637441">http://zenodo.org/record/2637441</a&gt

Parachromadorita Blome 1974

Genus <i>Parachromadorita</i> Blome, 1974 <p> The genus <i>Parachromadorita</i> was erected by Blome (1974) to accommodate <i>Dichromadora stygia</i>. Before that, Wieser (1954) transferred this species to <i>Denticulella</i> considering it as closely related to <i>Denticulella pellucida</i>. <i>Denticulella stygia</i> was then transferred to <i>Parachromadorita</i> by Blome (1974) based on the loop-shaped amphid. <i>Parachromadorita</i> is considered close to <i>Chromadora</i>, <i>Chromadorita</i> and <i>Dichromadora</i>, but it is distinguished by the morphology of the buccal cavity, the type of lateral differentiation of the cuticle and the shape of the amphideal fovea.</p> <p> <b>Diagnosis</b> (modified from Tchesunov 2014): Cuticle homogenous with lateral differentiation of irregular larger dots not arranged into longitudinal rows. Anterior sensilla in three separate circles. Amphideal fovea loop shaped. Buccal cavity with a large dorsal tooth, two smaller ventrosublateral teeth and a field of denticles. Peribuccal pharyngeal tissue swollen dorsally; pharynx ending in a single and pear-shaped bulb. Males with precloacal supplements. Marine.</p>Published as part of <i>Venekey, Virag, Gheller, Paula F., Kandratavicius, Noelia, Cunha, Beatriz Pereira, Vilas-Boas, Ana Carolina, Fonseca, Gustavo & Maria, Tatiana F., 2019, The state of the art of Chromadoridae (Nematoda, Chromadorida): a historical review, diagnoses and comments about valid and dubious genera and a list of valid species, pp. 1-67 in Zootaxa 4578 (1)</i> on page 43, DOI: 10.11646/zootaxa.4578.1.1, <a href="http://zenodo.org/record/2637441">http://zenodo.org/record/2637441</a&gt

Harpagonchinae Platonova & Potin 1972

Subfamily Harpagonchinae <p>Diagnosis (modified from Decraemer & Smol 2006 and Tchesunov, 2014): Cuticle with homogenous ornamentation without lateral differentiation. Anterior sensilla in three separate circles with the four cephalic sensilla setiform. Buccal cavity with three movable triangular-shaped mandibles with anterior solid hooks. Pharynx enlarged anteriorly around the mandibular apparatus and posteriorly widened with or without terminal bulb. Males with precloacal supplements present (cup-shaped) or absent. The genera of this sub-family are either considered ectoparasites (Decraemer & Smol 2006) or ectosymbionts (Tchesunov 2014) of polychaetes in marine environments.</p>Published as part of <i>Venekey, Virag, Gheller, Paula F., Kandratavicius, Noelia, Cunha, Beatriz Pereira, Vilas-Boas, Ana Carolina, Fonseca, Gustavo & Maria, Tatiana F., 2019, The state of the art of Chromadoridae (Nematoda, Chromadorida): a historical review, diagnoses and comments about valid and dubious genera and a list of valid species, pp. 1-67 in Zootaxa 4578 (1)</i> on page 32, DOI: 10.11646/zootaxa.4578.1.1, <a href="http://zenodo.org/record/2637441">http://zenodo.org/record/2637441</a&gt