Verônica da Fonsêca-Genevois

Bernardius lineatus gen. n., sp. n. (Enoplida: Enchelidiidae), a remarkable nematode with ornamented cuticle from a Brazilian tropical sandy beach

Bernardius lineatus gen. n., sp. n. is described from a sandy beach at Tamandare Bay, Brazil. It possesses the main characteristics of the family Enchelidiidae (Nematoda: Enoplida), but is unique by the presence of a body cuticle ornamented with longitudinal ridges formed by small rods, an entirely different character to all other members of the order Enoplida. The new genus is also characterised by a long, subdivided, buccal cavity with two subventral teeth and numerous denticles and the arrangement of the anterior sensilla in two crowns, the anterior crown being papilliform and the posterior crown consisting of six external labial and four cephalic sensilla, setiform. The relationships of the genera within the Enchelidiidae are discussed and an emended family diagnosis provided.

Five new species of Oncholaimellus (Oncholaimidae: Nematoda) from north-east Brazil, with an emended diagnosis and an updated key to the genus

Five new species of Oncholaimellus are described. They were found in macrofauna samples from the continental shelf in the Potiguar Basin, north-east Brazil. Cuticular pores with a sclerotized outline associated with a gland were observed in some species. Oncholaimellus multiporus sp. nov. is differentiated from other species by the presence of cuticular pores of different sizes; the smaller pores are abundant and give an appearance of ornamentation. Oncholaimellus intersexus sp. nov. and O. distortus sp. nov. are similar, but differ in the size of the external labial and cephalic setae compared to the corresponding diameter, the presence of the cuticular pores and the tail shape. Oncholaimellus paulus sp. nov. and O. sineporus sp. nov. are similar, although features such as the external labial and cephalic setae size compared to the corresponding diameter and the cuticular pores differentiate between them.

THE INFLUENCE OF TIDAL AND RAINFALL CYCLES ON INTERTIDAL NEMATODES: A CASE STUDY IN A TROPICAL SANDY BEACH

O presente estudo descreve a associacao de nematodeos da Baia de Tamandare (Brasil), praia arenosa tropical tipica, durante as mares (baixa, enchente, alta e vazante) de dois ciclos de mare consecutivos, em quatro meses diferentes do ano (Maio, Julho, Setembro e Novembro). A associacao de nematodeos foi dominada por Metachromadora e Perepsilonema e variou significativamente entre meses e mares. Densidades foram mais baixas em julho e as mudancas na associacao ocorreram durante meses de transicao entre chuvoso e seco mostrando a influencia do ciclo de chuvas. No ciclo de mare a enchente e vazante pareceram exercer a maior influencia, embora os padroes nao fossem muito claros. Recomenda-se que os estudos devam ser feitos ao nivel de generos/especies para melhor compreensao dos padroes das associacoes de nematodeos durante ciclos de mares.

Free-living nematodes from a colonisation experiment in the upwelling area of Arraial do Cabo, Rio de Janeiro, Brazil: Lavareda decraemerae gen. n., sp n. and emended diagnosis of Cricolaimus Southern, 1914 (Plectida: Rhadinematidae)

Lavareda decraemerae gen. n., sp. n. is characterised by a cheilostom with a sclerotised ring bearing six anterior projections, a funnel-shaped to tubular stegostom, a large unispiral amphid with wide groove and males with a single precloacal setiform sensillum and 19 tubular supplements in a continuous series. The new species is similar to Cricolaimus coronatus in having the cheilostom consisting of a cuticularised ring with anterior projections. Re-examination of C. elongatus revealed clear differences to the new species, the former showing a bilateral symmetry anteriorly with a lateral axis: the lips are merged into one large dorsal and one large ventral lip with elongated inner and outer labial sensilla and the cheilostom has a cuticularised oblique ring, higher dorsally and ventrally than laterally, with two anteriorly directed claw-like projections, one mid-dorsal and one mid-ventral, whereas the new species has a radial symmetry with low lips with inner and outer labial papillae indistinct and a cheilostom with a cuticularised ring with six anteriorly directed projections, thereby justifying the proposal of Lavareda gen. n. to accommodate the new species from Brazil and L. coronatus comb. n. (= C. coronatus). An emended diagnosis of Cricolaimus is given. This is the first record of a species belonging to the Rhadinematidae colonising an artificial substrate.

Known and new species of Sabatieria Rouville, 1903 (Araeolaimida: Comesomatidae) from the southwest Atlantic (Campos Basin, Brazil)

Abstract In the Campos Basin, 12 species of Sabatieria were collected, 2 of which were new to science. Sabatieria labium sp. nov. is characterized by well-defined lips and a spiral amphideal fovea with 4.25–4.5 narrow turns, combined with cephalic setae 3 µm long and 7–8 small, pore-shaped supplements, gradually spaced further apart anteriorly. Sabatieria verteris sp. nov. possesses 8–10 minute, pore-shaped precloacal supplements, gradually spaced further apart anteriorly, and short, slightly sclerotized spicules. Additionally, redescriptions of Sabatieria flecha, S. fidelis, S. mortenseni, S. ornata and S. paracupida are presented. The collection of additional specimens of these species allowed a re-evaluation of morphological and/or morphometric variations.