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Issue: Vol. 5821 No. 4: 3 Jun. 2026
Type: Article
Published: 2026-06-03
DOI: 10.11646/zootaxa.5821.4.4
Page range: 501-516
Abstract views: 52
PDF downloaded: 3

Atypical reproductive processes in a new species of marine Nematoda Spirobolbolaimus franciscus sp. nov. (Desmodorida, Microlaimidae) from Brazil

Laboratório de Bentos. Departamento de Oceanografia – Universidade Federal de Pernambuco (Av. Prof. Moraes Rego; 1235 – Recife-PE – Brazil)
Laboratório de Bentos. Departamento de Oceanografia – Universidade Federal de Pernambuco (Av. Prof. Moraes Rego; 1235 – Recife-PE – Brazil)
Nematoda Brazilian coast deep sea spermatophore sperm cells reproduction

Abstract

A new deep-sea species of the genus Spirobolbolaimus, S. franciscus sp. nov., has been discovered. It closely resembles S. pernambucanus Manoel, Neres & Esteves 2024, in general appearance and head region. Still, it differs in terms of larger body size (average 2665 µm in males, 2563 µm in females) compared to 1716 µm (holotype), and longer spicules (average = 68 µm) compared to 54 µm, with a c’ value of 2 versus 4. However, the main diagnostic feature that distinguishes the new species from all other species of the genus is a previously unrecorded “pin”-like secretion structure in the males vas deferens, as well as the presence of an inner spermatophore-like structure with the wall formed by a similar derived secretory product in the females. The new species also closely resembles S. undulatus Shi & Xu 2016, in most features, such as body length, spicules length, and sperm cell size; however, it clearly differs in its feeding apparatus, having only three teeth and lacking numerous small additional teeth. Additionally, Spirobolbolaimus franciscus sp. nov. possesses elongated oval sperm cells and also presents pin-like structures with a triangular head and spiniform corpus. Both features are discussed.

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How to Cite

Silva, M.C.D. & Filho, J.S.R. (2026) Atypical reproductive processes in a new species of marine Nematoda Spirobolbolaimus franciscus sp. nov. (Desmodorida, Microlaimidae) from Brazil. Zootaxa, 5821 (4), 501–516. https://doi.org/10.11646/zootaxa.5821.4.4