New insights gained from museum collections: new deep-sea species of Typhlotanais (Tanaidacea, Typhlotanaidae) from Brazil

Abstract

Benthic samples collected along the Brazilian central continental margin from Espírito Santo State to Rio de Janeiro State (19° S to 24° S) during the last 20 years and at depths of 50–2200 m yielded the description of six new species of Typhlotanais in the deep-sea (> 200 m): Typhlotanais andradeorum sp. nov., T. bolarticulus sp. nov., T. ischnochela sp. nov., T. longiseta sp. nov., T. priscilae sp. nov. and T. spinibasis sp. nov. Within these species, we found members of four Typhlotanais morpho-groups as ‘cornutus’ group, ‘greenwichensis’ group, ‘spinicauda’ and ‘trispinosus’ group. Typhlotanais ischnochela sp. nov. exhibited the greatest bathymetric range, occurring from the continental shelf until the lower slope (46–1898.7 m depth). The bathymetric distribution of the other five species of Typhlotanais herein described were restricted to the slope. Tables of diagnostic characters of the Typhlotanais morpho-groups and an identification key to the species of Typhlotanaidae found in Brazil are provided. This work brings the total number of Tanaidacea known for Brazilian coast to 64 species, and the family Typhlotanaidae from Brazil is now represented by 11 species in five known genera.

Diversity under a magnifier lens: the case of Typhlotanaidae (Crustacea: Tanaidacea) in the N Atlantic

“…spinibasis is a slender-bodied typhlotanaid (8.5 L:W) and because of long setae in merus, carpus and propodus in pereopods 1–3 was classified to ‘ptrispinosus’ group (Błażewicz-Paszkowycz, 2007), while Ty. spinipes has biarticulate uropod rami (unriarticulate in Jurundurella ), long and slender antennule (short in Jurundurella ), and ventrodistal seta in propodus 2–3 (spine in Jurundurella ) 59 , 75 . Intriguingly, Ty spinipes , as Jurundurella , has long distal setae in pereopods 2–3 (Fig.…”

“…Typhlotanais bolarticulus Segadilha & Serejo, 2022 has been provisionally classified in the ‘cornutus’ group 59 . Because of its unarticulate exopod rami it could be specifically classified within the Brevitanais group-1, although several morphological characters highlight its morphological distinctiveness, e.g.…”

“…Typhlotanais adipatus —Tzareva (1982) 57 : 53–54; Larsen (2005) 60 : 216; Błażewicz-Paszkowycz (2007) 27 : 6, 25, 33–34, 46, 98, 126, 131; Błażewicz-Paszkowycz (2014) 61 : 484; Błażewicz-Paszkowycz et al (2014) 33 : 417–418, 427, 449; Segadilha & Serejo (2022) 59 : 21, 27.…”

“…Typhlotanais andeepae Błażewicz-Paszkowycz (2007) 27 : 26–27, 33, 126–131. Segadilha & Serejo (2022) 59 : 21, 27.…”

“…Sars (1899) 65 : 24, 25, pl. 11; Hansen (1913) 38 : 61; Kussakin and Tzareva (1972) 66 : 238; Błażewicz-Paszkowycz (2007) 27 : 6, 25, 33, 126, 131; Błażewicz-Paszkowycz et al (2019) 67 : 4; Stępień et al (2019) 55 : 3; Segadilha and Serejo (2022) 59 : 27.…”