Three new Batillipes species (Arthrotardigrada: Batillipedidae) from the Brazilian coast

Abstract

Three new tardigrade species, Batillipes brasiliensis sp. nov., Batillipes dandarae sp. nov. and Batillipes potiguarensis sp. nov., are described from shallow subtidal sediments of the Brazilian coast. B. brasiliensis sp. nov. and B. dandarae sp. nov. have toes 3 and 4 on leg IV different in length, so they can be included in the D group of species, while B. potiguarensis sp. nov., with toes 3 and 4 on leg IV equal in length belong to the A group. Batillipes brasiliensis sp. nov. is characterized by having an ala-like caudal expansion; cuticular projections on the coxal region of legs I-III, and lateral projections. The lateral projection located between the third and fourth legs is fringed with digit-shaped expansions. Batillipes dandarae sp. nov. has a dorsal blunt enlargement in the scapular region; a pointed triangular caudal appendage, and no lateral projections. The new species exhibits a sensorial spine on legs I inserted posteriorly and turning forward, and anus surrounded by a peculiar cuticular structure constituted by six platelets. Batillipes potiguarensis sp. nov. is characterized by a unique combination of characters: scapular region well developed, protruding laterally at the level of the first pair of legs; lateral blunt processes between legs, and prominent roundish caudal protrusion. In addition, the new species exhibits cephalic appendages with swollen tips, evident secondary clavae, and very short sense organs on the legs IV.

A closer look at Batillipes dicrocercus and new records of Batillipes potiguarensis (Tardigrada: Arthrotardigrada) from the Brazilian coast with comments on intra- and interspecific variability

“…2). The oblique shape of tarsi on the three first pairs of legs (also present in B. spinicauda Gallo D'Addabbo, Sandulli & de Zio Grimaldi, 2005) and dorsolateral punctations larger than mid-dorsal punctations observed in the specimens with bifurcated caudal apparatuses, were characters previously neglected by Santos et al (2017) in the original description, but they are also present in B. potiguarensis as confirmed in this study. On the other hand, specimens of different gender and age (males were not known until now), with and without bifurcated caudal appendage, occurred simultaneously in time and space in samples from the Potiguar Basin (all specimens collected in Campos Basin had bifurcated caudal apparatuses).…”

“…However, during a recent survey of marine tardigrades in the Brazilian states of Rio de Janeiro and Rio Grande do Norte mixed populations of Batillipes specimens exhibiting both a bifurcate caudal appendage or a roundish caudal protrusion as observed in B. potiguarensis Santos, da Rocha, Gomes Jr & Fontoura 2017, were collected. This fact demanded a deeper morphological study of B. potiguarensis, a species recently described from Brazil (Santos et al, 2017), in order to know if in this species the caudal apparatus also displays intraspecific variability or if the Batillipes from this collection belong to two distinct species. Moreover, a comparative study with B. dicrocercus was also necessary because the specimens with furcate caudal apparatuses could be attributed to this species, as it happened in the previously mentioned studies, or could belong to an undescribed species.…”

“…-8. Batillipes potiguarensisSantos, Rocha, Gomes Jr & Fontoura, 2017: 3, detail of a bifurcated caudal appendage; 4, posterior portion of the body, showing an asymmetric caudal appendage with one short spike only (arrowhead); 5, posterior portion of the body showing an asymmetric caudal appendage with one short spine only (white arrowhead). The black arrowhead shows the blunt lateral projection between legs III-IV; 6, caudal appendage without spines.…”

Tardigrades Research in Brazil: an overview and updated checklist

“…The biologist Clélia Márcia Cavalcanti da Rocha maintains a research group on the systematics and ecology of tardigrades, working mainly with marine tardigrades of the northeastern coast of Brazil (Rocha, 2018). Recently, her group described the new species Ligiarctus alatus Gomes Júnior, Santos, da Rocha, Santos & Fontoura, 2018 (Santos et al, 2017). Rocha also organized the first tardigrades scientific collection in Brazil (Rocha, 2018).…”

The Deep-Sea Genus Coronarctus (Tardigrada, Arthrotardigrada) in Brazil, South-Western Atlantic Ocean, with the Description of Three New Species

“…From these, only three species were recorded from abyssal depths in the Eastern coast (Angola and Namibia) of the South Atlantic Ocean, Angursa abyssalis Renaud-Mornant, 1981, A. lanceolata Renaud-Mornant, 1981, andCoronarctus tenellus Renaud-Mornant, 1974 [11,12]. So far, studies on Tardigrada in abyssal depths have not been performed for the Southwestern Atlantic Ocean, where 32 tardigrade species have been recorded from shallow intertidal and shallow sublittoral zones [13][14][15]. Another species, Ligiarctus alatus Gomes-Jr. et al, 2018, collected from depths of 100 to 150 m, is the deepest tardigrade record in this region [16].…”