A Hidden Diversity in the Atlantic and the SE Pacific: Hamatipedidae n. fam. (Crustacea: Tanaidacea)

Abstract

A new family of paratanaoidean Tanaidacea, the hamatipedids, formerly part of the Typhlotanaidae, is established to accommodate three genera (Hamatipeda and two new). Deep-sea hamatipedids collected from four sites in the Atlantic (Argentine and Guiana basins) and 14 sites from the Southeast coast of Australia were studied using a taxonomic approach combining morphological and morphometric data. Four new species of Hamatipeda and one of a new genus are described from different deep-sea areas of the Atlantic and Pacific oceans. Hamatipeda sima originally classified within Hamatipeda, is transferred to a new genus. We observed that several morphometric characters (i.e., length of the last two pereonites) in different life-stages of one of the new Hamatipeda species (neuter, manca-2, and manca-3) are correlated with the total body length (TBL). Applying a morphometric approach, we aimed: (1) to identify those ontogenetic-dependent characters, and (2) to detect the characters, which can be used in discrimination of Hamatipedidae species, regardless their life-stage.

Deeper diversity exploration: New Typhlotanaidae (Crustacea: Tanaidacea) from the Kuril-Kamchatka Trench area

“…The 'comb-like' scales present on antennules, antennae, and chelipeds are homologous to the so-called microtrichia from previous Tanaidacea studies (Bird, 2004;Błazėwicz-Paszkowycz, 2007a). The term 'clinging apparatus' (= prickly tubercles) refers to a system of various hooks, tubercles, thorns, and spines, located on the carpus of pereopods 4-6 (Błazėwicz-Paszkowycz, 2007a;Gellert et al, 2022). The distal part of the cheliped basis, extending backward, is referred to here as 'cheliped lobe' (Larsen, 2005).…”

Mislabeling and nomenclatorial confusion of Typhlotanais sandersi Kudinova-Pasternak, 1985 (Crustacea: Tanaidacea) and establishment of a new genus

“…The clinging apparatus is a system of various hooks, tubercles, thorns, and spines located on the carpus of pereopods 4−6 ( Błażewicz-Paszkowycz, 2007a ; Gellert et al, 2022 ). Unspecified setae in taxonomic descriptions are referred here as simple setae (= without ornamentation) by default.…”

Diversity under a magnifier lens: The case of Typhlotanaidae in N Atlantic

“…From the total number of 115 species typhlotanaid species, 31% are known only from that region. The family is recognized to be highly diverse and its anticipated polyphyletic nature was frequently underlined 19,20,25,61,62 . Nevertheless, the paucity of morphological and genetic data, especially related to the deep-sea taxa, obscure the bounds of infra-and intraspecific variation, and hampers phylogenetic inferences centred on the morphology 20,35,[62][63][64] .…”

“…Unspecified setae in the taxonomic descriptions are termed simple setae by default. The clinging apparatus (= prickly tubercles) is a system of various hooks, tubercles, thorns, and spines located on the carpus of pereopods 4−6 19,20,62 . The short ventral seta situated besides two long setae on the chelipeds carpus is called 'third' seta.…”