Anchistioididae, Borradaile, 1915

Caridea, Anchistioididae , Palaemonidae , Demospongiae, symbiosis.

Despite being less numerous than free-living species, symbiotic decapod crustaceans are quite common and this lifestyle has evolved independently in several taxa within the group ( Bauer, 2004; Baeza et al., 2011). Among decapods, caridean shrimps have been commonly reported in association with larger invertebrates and even with fishes (e.g., Castro, 1971; Bruce, 1976; Knowlton and Keller, 1983; Karplus, 1987; Bauer, 2004). However, the true kind of symbiosis between shrimps and their hosts remains unknown in most cases and, for this reason, the term “association” has been used to describe such interactions ( Bauer, 2004).

Caridean shrimps generally use cavities, cracks or even the inside of sessile organisms as shelters, breeding sites or as refuge from predators. Sponges are one of the main hosts of caridean shrimps (e.g., Bruce, 1976; Anker et al., 2008; Pachelle et al., 2015). The type of the associations varies from facultative to obligatory symbiosis ( Bruce, 1976). Some snapping shrimps of the genus Synalpheus Spence Bate, 1888 , for example, are obligatory sponge symbionts ( Duffy, 1992; Macdonald et al., 2006; Ríos and Duffy, 2007).

During a survey of caridean shrimps carried out in the Abrolhos Archipelago, Bahia, Brazil, Soledade et al. (2015) registered 11 new shrimp records from this region, with some species collected in association with sponges; however, the identity of the host sponges was not elucidated at that time. Recently, the sponges were identified and we verified that some of them were never previously registered in association with two caridean shrimps that occur in the area. Thus, the objective of this study is to report these new associations and to provide a new record of one of the sponge hosts in the Abrolhos Archipelago. To infer about the kind of association between shrimps and sponges we reviewed previous records of associations of species of shrimp with different hosts, and also took into consideration the location of the shrimps inside the sponges.

The material analyzed was obtained in coral reefs surrounding Santa Barbara Island (17°57’49”S 38°41’53”W). The sponges were collected between 22 th July and 4 th August 2013. Once collected, the specimens were placed in plastic bags (in situ) to prevent escape of associated organisms GoogleMaps .

In the laboratory, the sponges were carefully inspected, and the associated fauna was removed, anesthetized on ice, and fixed in ethanol 70%. The associated shrimp were identified and deposited in the Crustacean Collection of the Museu de Oceanografia of Universidade Federal de Pernambuco, Recife, Brazil (MOUFPE). The sponges were deposited in the Coleção de Porifera of Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil [ Amphimedon viridis Duchassaing & Michelotti, 1864 , UFPEPOR 1890, Fig. 1A View Figure 1 ; Dysidea janiae ( Duchassaing & Michelotti, 1864) , UFPEPOR 1892, Fig. 1B View Figure 1 ].