A new species of Robertsella Guinot, 1969 (Crustacea: Brachyura: Panopeidae) from the southwestern Atlantic

Abstract

A new species of deep-water brachyuran crab, Robertsella meridionalis, from Brazil is described and illustrated. The new species can be easily separated from its northwestern Atlantic counterpart, R. mystica Guinot, 1969, by a suite of carapace and appendage characters. Robertsella mystica is redescribed and illustrated. Putative sound-producing structures in the genus Robertsella are first described.

New distributional records of species of the family Pseudorhombilidae Alcock, 1900 (Crustacea: Decapoda) from Brazilian waters

“…Remarks. The characteristics of the R. meridionalis specimens were consistent with the original description provided by Tavares and Gouvêa (2013), who listed some morphological differences between the only two described species of the genus Robertsella. The species of R. meridionalis can be distinguished from R. mystica by the following characters: strongly def lexed frontal region of carapace (Fig.…”

“…3C) (vs. proportionally larger) (see more characteristics in Tavares and Gouvêa, 2013). The genus Robertsella was recorded only once in the original description of R. meridionalis provided by Tavares and Gouvêa (2013), specifically from the southern region of Brazil (state of Santa Catarina) from a depth of 400 m. Thus, the present work provides a second report of the species R. meridionalis from Brazil (Northeast region -Potiguar Basin) at about 4,200 km distance from the type locality and increases the bathymetric distribution range for this species to 180-400 m.…”

“…The collected specimens were sorted, preserved in 70 % ethanol, and identified to the species level with the aid of relevant descriptions provided by Guinot (1969a), Hernández Aguilera (1982, and Tavares and Gouvêa (2013). In addition, many other papers were used to form a synonymic list that assisted in filling the gaps on the geographic and bathymetric information for each species examined.…”

“…Nauplius, 29: e2021016 Geographic distribution. Western Atlantic: Brazilian states of Rio Grande do Norte (Potiguar Basinpresent record) and Santa Catarina (Tavares and Gouvêa, 2013) (Fig. 5).…”

First record and a new species of Euphrosynoplax (Crustacea: Pseudorhombilidae) from the southwestern Atlantic

“…The north-south disjunct distribution pattern of Euphrosynoplax is highly comparable to those of other moderately deep-water decapods, such as Eumunida, Neopilumnoplax, Robertsella, Speocarcinus and Trichopeltarion (Brandão et al, 2010(Brandão et al, , 2012Tavares & Melo 2005Tavares & Gouvea, 2013;Tavares & Lima 2019). Such distribution gaps may well be only the result of poor distributional information and detectability, as exemplified by the deep-water genus Chaceon, whose fragmented distribution of some of its southwestern Atlantic representatives has been slowly filled as a result of the intensification of deep-water commercial fishing and detection facilitated by the species' large size (Manning & Holthuis, 1989;Tavares & Pinheiro, 2011).…”