A new species of parasitic isopod (Bopyroidea: Ionidae) infesting burrowing shrimp (Axiidea: Callianassidae) in the tropical eastern Pacific.

A new species of parasitic isopod in the genus Ione Latreille, 1818, infesting the branchial chamber of the intertidal burrowing shrimp Neotrypaea tabogensis (Sakai, 2005) is described on the basis of material collected on the Pacific coast of Costa Rica. Diagnostic features of the new species include: (1) body shape of female asymmetrical with slight left distortion, pereon segments distinct; (2) head of female not fused with first pereomere, posterior margin nearly straight; (3) antenna of female composed of five articles; (4) posterior lamella of barbula of female with two tapered lobes on each side; (5) body of male elongated, clearly segmented dorsally; (6) head of male completely separated from the first pereomere; and (7) maxillipeds absent in male. This is the seventh valid species in the genus Ione and the first record of this genus from the tropical eastern Pacific.

Monogamy in the Burrowing Shrimp Rodrigues & Shimizu, 1992 (Decapoda, Gebiidea, Axianassidae).

Our knowledge of the mating systems in burrowing shrimps (infraorders Axiidea and Gebiidea) is still rather limited. Here we describe the burrow use pattern, sex ratio, and sexual dimorphism of the burrowing shrimp to test for monogamy, considering that monogamous species live in heterosexual pairs and exhibit a low degree of sexual dimorphism. To this end, a total of 226 individuals of were collected from the northeast region of Brazil.

Validation of the Pleistocenic ghost shrimp Callichirus santensis Hernáez, Buchmann amp; Santana† (Decapoda: Callianassidae) from the southwestern Atlantic.

Hernáez et al. (2020) described a new fossil species of ghost shrimp, Callichirus santensis, from the Upper Pleistocene Cananéia Formation, southeast Brazil. The article in which C.

Validation of the ghost shrimp species Neocallichirus pinheiroi Hernáez, Windsor, Paula amp; Santana (Decapoda: Callianassidae) from the southwestern Atlantic.

Hernáez et al. (2020) described a new species of ghost shrimp, Neocallichirus pinheiroi, from northeastern coast of Brazil, Western Atlantic. Although the description and figures presented by Hernáez et al.

A new species of Biffarius Manning amp; Felder, 1991 (Decapoda: Axiidea: Callianassidae) from the intertidal coast of northeastern Brazil.

A new species of intertidal ghost shrimp, Biffarius botterae, is described from Maranhão and Ceará in northeastern Brazilian coast. Diagnostic features of the new species include: (1) antennular peduncle shorter than antennal peduncle; (2) male major cheliped massive; (3) male pleopod 2 uniramous, vestigial; (4) uropodal endopod widening distally, inner lateral margin convex; and (5) anterodorsal plate of uropodal exopod absent. Biffarius Manning Felder, 1991, now consists of four species: B.

A new species of Callianidea H. Milne Edwards, 1837 (Decapoda, Axiidea, Callianideidae) from the Pacific Coast of Central America, with key to the genus.

A new callianideid species, Callianidea mariamartae n. sp. is described from the Pacific coast of Costa Rica.