The scleractinian Agaricia undata as a new host for the coral-gall crab Opecarcinus hypostegus at Bonaire, southern Caribbean

Abstract

The Caribbean scleractinian reef coral Agaricia undata (Agariciidae) is recorded for the first time as a host of the coral-gall crab Opecarcinus hypostegus (Cryptochiridae). The identity of the crab was confirmed with the help of DNA barcoding. The association has been documented with photographs taken in situ at 25 m depth and in the laboratory. The predominantly mesophotic depth range of the host species suggests this association to be present also at greater depths. With this record, all seven Agaricia species are now listed as gall-crab hosts, together with the agariciid Helioseris cucullata. Within the phylogeny of Agariciidae, Helioseris is not closely related to Agaricia. Therefore, the association between Caribbean agariciids and their gallcrab symbionts may either have originated early in their shared evolutionary history or later as a result of host range expansion. New information on coral-associated fauna, such as what is presented here, leads to a better insight on the diversity, evolution, and ecology of coral reef biota, particularly in the Caribbean, where cryptochirids have rarely been studied.

Diversity and distribution of coral gall crabs associated with Red Sea mesophotic corals

“…Further investigation of mesophotic reefs is necessary to understand the role of depth on reef-affiliated invertebrates and to unravel the mesophotic diversity and depth zonation of cryptic reefassociated taxa, such as the gall crabs. Moreover, it is crucial to deepen our understanding of cryptochirids concerning their bathymetrical ranges and phylogenetic relationships of their host taxa to comprehend the evolutionary history of these mesophotic associations (Garcıá-Hernańdez et al, 2020) and to understand the role they play in coral reef ecosystems (Stella et al, 2011), in light of the current climate change scenario and consequent reef degradation.…”

Diversity, host specificity and biogeography in the Cladocorynidae (Hydrozoa, Capitata), with description of a new genus

“…Overall, a certain degree of host specificity can be detected, mostly at the family level, even if with some exceptions. Host specificity has recently been demonstrated for several other coral‐reef invertebrates associated with a variety of benthic organisms, such as parasitic gastropods (Gittenberger and Gittenberger, 2011; Gittenberger and Hoeksema, 2013; Potkamp et al., 2017; Fritts‐Penniman et al., 2020), coral‐dwelling barnacles (Malay and Michonneau, 2014; Tsang et al., 2014), commensal shrimps (Horká et al., 2016), copepods (Korzhavina et al., 2019), benthic ctenophores (Alamaru et al., 2017), coral gall‐crabs (García‐Hernández et al., 2020), acoel flatworms (Kunihiro et al., 2019), and hydrozoans (Maggioni et al., 2020b, c). Host‐specificity of associated species can be very weak as observed in various coral‐dwelling copepods living on mushroom corals (Ivanenko et al., 2018) and in one serpulid worm living on a wide range of Caribbean scleractinians (Hoeksema and Hove, 2017).…”

Diversity of coral-associated pit crabs (Crustacea: Decapoda: Cryptochiridae) from Hong Kong, with description of two new species of Lithoscaptus A. Milne-Edwards, 1862

“…The several species herein reported from Hong Kong can be referred to as "pit crabs," and we refrain from referring cryptochirids exclusively as "gall crabs." However, given the considerable diversity of cryptochirid domiciles, such as those lodged between septa of mushroom coral of the Fungiidae (Hoeksema et al, 2012;van der Meij et al, 2015), and some forming a canopy-like structure, partially sheltering the opening in hosts of the Agariciidae (Hoeksema et al, 2017;Garcıá-Hernańdez et al, 2020), further definition of common names of cryptochirid crabs based on their domicile morphology may require further investigations.…”