Southern hemisphere deep-water stylasterid corals including a new species, Errina labrosa sp. n. (Cnidaria, Hydrozoa, Stylasteridae), with notes on some symbiotic scalpellids (Cirripedia, Thoracica, Scalpellidae)

Abstract

A number of stylasterid corals are known to act as host species and create refuges for a variety of mobile and sessile organisms, which enhances their habitat complexity. These include annelids, anthozoans, cirripeds, copepods, cyanobacteria, echinoderms, gastropods, hydroids and sponges. Here we report the first evidence of a diverse association between stylasterids and scalpellid pedunculate barnacles and describe a new stylasterid species, Errina labrosa, from the Tristan da Cunha Archipelago. Overall, five stylasterid species are found to host eight scalpellid barnacles from several biogeographic regions in the southern hemisphere (Southern Ocean, temperate South America and the southern Indo-Pacific realms). There is an apparent lack of specificity in this kind of association and different grades of reaction to the symbiosis have been observed in the coral. These records suggest that the association between pedunculate barnacles and hard stylasterid corals has a wide distribution among different biogeographic realms and that it is relatively rare and confined largely to deep water.

Microboring organisms in living stylasterid corals (Cnidaria, Hydrozoa)

“…They are mainly distributed in deeper waters, where they constitute important components of so-called 'cold water coral gardens' (Cairns 2011). They are also considered habitat-forming species in shallow waters (Häussermann & Försterra 2007) with a wide range of associated organisms (Zibrowius 1981;Goud & Hoeksema 2001;Pica et al 2012Pica et al , 2015. In tropical live stylasterids, the presence of euendoliths was first suggested by Broch (1942), who studied Distichopora borealis japonica Broch, 1942 from Okinose, Japan (110 m depth) and Distichopora violacea (Pallas, 1766) (as D. fisheri Broch, 1942) from Levu, Fiji Islands (depth unknown).…”

Distribution and habitat of Scalpellidae (Cirripedia: Thoracica) in the Norwegian and Barents Seas

“…Scalpellid cirripeds are attached to the substrate at the base of the peduncle and mainly use other organisms as substratum, e.g. hydrozoans, bryozoans, echinoderms and corals (Buhl-Mortensen and Mortensen 2005;Buhl-Mortensen and Høeg 2006;Pica et al 2015). Their body and inner organs are hidden inside the capitulum and only the 'cirri', appendages used for filter feeding, are visible outside.…”

Widespread Occurrence of a Rarely Known Association between the Hydrocorals Stylaster roseus and Millepora alcicornis at Bonaire, Southern Caribbean

“…Their colonies are generally erect and branching with only the Pacific genus Stylantheca Fisher, 1931 having an encrusting morphology [18]. Most lace corals, including those of the genus Stylaster Gray, 1831, are known to form strict relationships with other invertebrates [18,19]. Stylasterids are host of a number of commensals such as polychaetes [20][21][22], nemerteans, pycnogonids, cirripids, barnacles, and bryozoans [23,24].…”