Host specificity of coral-associated fauna and its relevance for coral reef biodiversity

Stony Corals and Their Associated Fauna Residing in Marine Lakes under Extreme Environmental Conditions

“…Boring sponges may also occur in marine lakes and have here only been recorded from limestone rock but not yet from corals [70,71], as those in open-sea reefs [71][72][73][74]. Other large, striking coral-associated fauna, such as worm snails [75][76][77], barnacles, and gall crabs [49,78,79], were also not observed in the marine lakes of Raja Ampat, and should therefore receive more attention in future studies.…”

“…Clusters of the box mussel bivalve, Septifer bilocularis (family Mytilidae), were present in high densities over the upper surface of massive coral colonies and inside crevices (Figure 6a-c). Boring mussels of the genus Leiosolenus (previously also known as Lithophaga) of the same family lived inside massive Porites corals, showing their characteristic orifices [46][47][48][49] scattered over their host's surface (Figure 6d). The shell ribs of Septifer bilocularis resemble those of Brachidontes spp., which were also found to be abundant in the lakes but not in association with corals [22].…”

“…The only serpulid worm that could be identified was Floriprotis sabiuraensis (Figure 7d-f), a coral symbiont, which has been reported from various hosts and localities across the Indo-Pacific [49,[63][64][65]. The calcareous tube of an unknown serpulid was found attached to the surface of a massive coral (Figure 7g).…”

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

“…In fact, Leptoseris is one of the most abundant scleractinian genera in MCEs (Fricke et al, 1987;Hinderstein et al, 2010;Rooney et al, 2010;Kahng et al, 2014, Kahng et al, 2017Loya et al, 2019). The strict association between gall crabs and scleractinian corals and the cryptochirid host specificity at host species, genera, or families (e.g., van der Meij, 2015avan der Meij, , 2015bvan der Meij et al, 2015;Bähr et al, 2021;Xu et al, 2022;van der Schoot and Hoeksema, 2024) led to hypothesize that the number of host corals could predict the number of cryptochirids (van der Meij, 2015a; van der Schoot and Hoeksema, 2024). Moreover, Kohn and Leviten (1976) showed that habitat availability affects the abundance and diversity of coral-associated invertebrates.…”

“…To shed light on the biology and the ecology of MCEs, a focus on overlooked reef-associated invertebrates, such as cryptochirids, is crucial. In fact understanding how the diversity and ecology of coralassociated invertebrates change with increasing depth can be useful to establish the reef-associated invertebrates' roles within coral reef ecosystems, especially in regard to their impact on reef resilience, and can inform the steps needed for their conservation (Stella et al, 2011;van der Schoot and Hoeksema, 2024). In this context, Red Sea scleractinian corals are known to host nine cryptochirid species ascribed to the genus Opecarcinus, mostly occurring in shallow water (< 30 m) (Xu et al, 2022), with the notable exception of the depth generalist Opecarcinus identified by the preliminary code SET4 (Xu et al, 2022), recovered on one Leptoseris cf.…”