Integrative systematics and ecology of a new deep-sea family of tanaidacean crustaceans

Magdalena Błażewicz,Inmaculada Frutos,Piotr Jóźwiak,Robert M. Jennings,Maciej Studzian

doi:10.1038/s41598-019-53446-1

Abstract

A new family of paratanaoidean Tanaidacea – Paranarthrurellidae fam. nov. – is erected to accommodate two genera without family classification (Paratanaoidea incertae sedis), namely Armatognathia Kudinova-Pasternak, 1987 and Paranarthrurella Lang, 1971. Seven new species of Paranarthrurella and two of Armatognathia are described from material taken in different deep-sea areas of the Atlantic and Pacific oceans. The type species of Paranarthrurella — P. caudata (Kudinova-Pasternak, 1965) — is redescribed based on the paratype. The genus Cheliasetosatanais Larsen and Araújo-Silva, 2014 originally classified within Colletteidae is synonymised with Paranarthrurella, and Arthrura shiinoi Kudinova-Pasternak, 1973 is transferred to Armatognathia. Amended diagnoses of Armatognathia and Paranarthrurella genera are given. Choosing characters for distinguishing and defining both genera was supported by Principal Component Analysis. Designation of the new family is supported by molecular phylogenetic analysis of COI and 18S datasets. The distribution of all species currently included in the new family was visualised and their bathymetric distribution analysed.

Highlights

A new family of paratanaoidean Tanaidacea – Paranarthrurellidae fam. nov. – is erected to accommodate two genera without family classification (Paratanaoidea incertae sedis), namely Armatognathia Kudinova-Pasternak, 1987 and Paranarthrurella Lang, 1971
During examination of the Tanaidacea from various collections made in different deep-sea parts of the Atlantic and the Pacific oceans, we have revealed a series of distinct species, which we classified to two genera: Paranarthrurella and Armatognathia
Morphological analysis of 87 individuals provisionally classified to Paranarthrurella allowed the observation of a series of morphological features (e.g.: left mandible lacinia mobilis broad, widely separated from incisor forming “spoon-like” gap, rounded and swollen pleon) which are present in a few other species known from the literature, such as Armatognathia birsteini Kudinova-Pasternak, 1987 and the tanaellid Arthrura shiinoi Kudinova-Pasternak, 1973, and the colletteid recently described Cheliasetosatanais spinimaxillipedus Larsen & Araújo-Silva, 2014

Summary

Introduction

A new family of paratanaoidean Tanaidacea – Paranarthrurellidae fam. nov. – is erected to accommodate two genera without family classification (Paratanaoidea incertae sedis), namely Armatognathia Kudinova-Pasternak, 1987 and Paranarthrurella Lang, 1971. The tanaidacean tanaidomorph genus Paranarthrurella was established by Lang (1971)[1] to accommodate a conspicuous species described by Kudinova-Pasternak in 19652 — Leptognathia caudata Kudinova-Pasternak, 1965. Four currently known nominal species of the genus Paranarthrurella (P. arctophylax (Norman and Stebbing, 1886), P. caudata (Kudinova-Pasternak, 1965), P. dissimilis (Lang, 1972) and P. voeringi (Sars, 1877)), have historically been classified primarily to six distinct genera, namely: Tanais Latreille, 18315,6, Cryptocope Sars, 18827,8, Leptognathia Hansen, 19131,3,9–11, Strongylura (synonymized with Collettea)[12], Biarticulata (=Leptognathia)[13], and monotypic Robustognathia (=Paranarthrurella)[4].

Methods

Results

Conclusion