Three new species of Microlaimus (Nematoda: Microlaimidae) from the South Atlantic

PeerJ. 2022 Mar 9:10:e12734. doi: 10.7717/peerj.12734. eCollection 2022.

Abstract

Three new species of Microlaimus are described from the continental shelf of the Campos Basin, southwest Atlantic, Brazil. Microlaimus campiensis sp. n. differs from all other species in the presence of two anterior testes, slender spicules with enlarged proximal ends, 7-11 pre-cloacal papilliform supplements, and females with a pair of constriction structures, one on each branch of the ovary. Microlaimus alexandri sp. n. shows sexual dimorphism in the size of the amphidial fovea, which occupies 100% of the diameter of the corresponding area in the male; the buccal cavity provided with five teeth and a slightly cuticularized cuticular ring. Microlaimus vitorius sp. n. has four longitudinal-lateral rows of glands associated with small pores, one seta and three pores small pre-cloacal, and the gubernaculum has a triangular base. An amendment to the diagnosis of the genus is proposed, where the number of teeth was modified.

Keywords: Campos basin; Continental shelf; MEIOFAUNA; Marine nematodes; New species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brazil
  • Chromadorea
  • Dietary Supplements
  • Female
  • Inferior Colliculi*
  • Male
  • Nematoda*

Grants and funding

This work was supported by the ‘Habitats Project—Campos Basin Environmental Heterogeneity’ of CENPES/PETROBRAS by collecting the samples and providing the opportunity to study them. Andre M. Esteves (CNPq 310249/2019-8) was supported by a research fellowship from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.