Paratyphlotanais Kudinova-Pasternak & Pasternak, 1978

Segadilha, Juliana Lopes, Serejo, Cristiana Silveira & Błażewicz, Magdalena, 2019, New species of Typhlotanaidae (Crustacea, Tanaidacea) from the Brazilian coast genera Hamatipeda, Meromonakantha and Paratyphlotanais, with description of Targaryenella gen. nov., Zootaxa 4661 (2), pp. 309-342 : 326

Genus Paratyphlotanais Kudinova-Pasternak & Pasternak, 1978

LSID urn:lsid:zoobank.org:act:6EA7E497-DCCC-4865-98BE-2784C3F3BE83

Diagnosis (Modified after Bird, 2004): Body long, about 6–8 times L:W; cephalothorax longer than wide, gener- ally conical; at least pereonite-1 with sternal spurs (hyposphenia); antennule never longer than carapace; article-3 with terminal spur; mandible with broad crushing molar nodulose (except P. bessai with undulations and teeth); maxilliped basis with long seta at least as long as endites; endite not fused, with gustatory cusps; cheliped attached via small sclerite; basis not reaching pereonite-1, ventrally or with small gap between ( P. apletos ); merus with 1–5 ventral setae; carpus with 2–8 ventral setae; pereopods 1–2 coxa with or without spur; pereopods 2–3 carpus with dorsal and ventral spines; pereopods 2–6 merus and carpus with serrate spines; pereopods 4–6 unguis bifurcate; pleopods present, both rami with setae on lateral and distal margin and gap between most proximal seta and others; uropods slender, as long as or longer than pleotelson; endopod two-articled, distal article much shorter than proximal; exopod one- or two-articled.

Type species: Paratyphlotanais typicus Kudinova-Pasternak & Pasternak, 1978 .

Species included: Paratyphlotanais alveolus Błażewicz-Paszkowycz, 2007 ; P. (= Typhlotanais ) armatus ( Vanhöffen, 1914) ; P. colouros Błażewicz-Paszkowycz & Bamber, 2012 ; P. (= Typhlotanais ) gracilipes ( Hansen, 1913) ; P. japonicus Kudinova-Pasternak, 1984 ; P. (= Typhlotanais ) mananensis ( Wallace, 1919); P. (= Typhlotanais ) microcheles ( Sars, 1882) ; P. pectinatus Bird, 2004 ; P. (= Typhlotanais ) richardi ( Dollfus, 1897); P. typicus Kudinova- Pasternak & Pasternak, 1978; P. apletos sp. nov. (see below); P. bessai sp. nov. (see below).

Remarks. Kudinova-Pasternak & Pasternak (1978) in describing the genus mentioned that Paratyphlotanais differs from Typhlotanais by the last three pairs of pereopods (P4–6), which are not greatly expanded (= stouter) compared with the first pairs (P1–3) and not armed with “complex spikes” and rows of spines (= prickly tubercles); in addition to slender uropods, which are equal to the length of the pleotelson and the last two pleonites together. Bird (2004) characterized the genus by: the cephalothorax longer than wide, distinctly conical; at least pereonites 1–2 with hyposphenia; antenna articles 2–3 with dorsal “spiniform seta” (= stout seta, not spine); pereopods 2–6 merus and carpus with long serrate spines; uropods slender, endopod two-articled with distal article, that is much shorter than proximal. Both new species described below fit the diagnosis according to this author, except that their cephalothorax is not typically conical. Nevertheless, as the shape of cephalothorax can vary within genus, the presence of long serrate spines on pereopods 2–6 merus and carpus should be an important conspicuous character to distinguish the group.

Morphological variation in generic characters is found within Tanaidacea ( Larsen 2001) . In the genus Paratyphlotanais there are some differences among number of setae and presence or absence of a coxal spur ( Table 5 ). Paratyphlotanais armatus , P. colouros , P. japonicus , P. microcheles , and P. typicus do not have a spur on pereopod-1 or on pereopod-2. However, P. alveolus has the spur only on pereopod-1 and P. gracilipes and P. pectinatus have a coxal spur on both pereopods. All described species, except P. pectinatus have a seta on the ischium of pereopods 1–3; P. alveolus and P. typicus have only one seta on the ischium of pereopods 4–6, while most species have two. In relation to cheliped carpus setae, there is a big variation from 1–10 (dorsal) and 2–8 (ventral), even intraspecific where we found individuals of the new species P. apletos described below that have 9–10 (dorsal) and 7–8 (ventral) setae. Finally, the only species with uropod exopod two-articled is P. pectinatus . Further investigations should be carried out in order to better understanding of these morphological variations in the issue of representing generic or specific differences.