Stylobates birtlesi sp. n., a new species of carcinoecium-forming sea anemone (Cnidaria, Actiniaria, Actiniidae) from eastern Australia.

Andrea L Crowther,Carden C Wallace,Daphne G Fautin

doi:10.3897/zookeys.89.825

Andrea L Crowther, Carden C Wallace + Show 1 more

Open Access

https://doi.org/10.3897/zookeys.89.825

Copy DOI

Journal: ZooKeys	Publication Date: Apr 11, 2011
Citations: 16	License type: CC BY 3.0

Affiliation: American Museum of Natural History, University of Kansas

Abstract

We describe a new species of carcinoecium-forming sea anemone, Stylobates birtlesi sp. n., from sites 590–964 m deep in the Coral Sea, off the coast of Queensland, Australia. An anemone of this genus settles on a gastropod shell inhabited by a hermit crab, then covers and extends the shell to produce a chitinous structure termed a carcinoecium. Stylobates birtlesi sp. n. is symbiotic with the hermit crab Sympagurus trispinosus (Balss, 1911). The nature of marginal sphincter muscle and nematocyst size and distribution distinguish Stylobates birtlesi sp. n. from other species in the genus. The four known species of Stylobates are allopatric, each inhabiting a separate ocean basin of the Indo-West Pacific. We also extend the known range of Stylobates loisetteae in the Indian Ocean off the coast of Western Australia.

Highlights

Stylobates Dall, 1903, of family Actiniidae Rafinesque, 1815, is an exclusively deepwater genus of sea anemones in which three species are known: Stylobates aeneus Dall, 1903, from Hawai’i and Guam in the Pacific Ocean, Stylobates cancrisocia (Carlgren, 1928a), from the Indian Ocean off Africa, and Stylobates loisetteae Fautin, 1987, from the Indian Ocean off Western Australia
Because Dall (1903) had been under the impression that the carcinoecium upon which he based his description was that of a gastropod, the first description of the anemone was by Carlgren (1928a) for Isadamsia cancrisocia from the east coast of Africa
Deep-sea Actiniidae with very wide pedal disc that covers a gastropod shell inhabited by a hermit crab

Summary

Introduction

Stylobates Dall, 1903, of family Actiniidae Rafinesque, 1815, is an exclusively deepwater genus of sea anemones in which three species are known: Stylobates aeneus Dall, 1903, from Hawai’i and Guam in the Pacific Ocean, Stylobates cancrisocia (Carlgren, 1928a), from the Indian Ocean off Africa, and Stylobates loisetteae Fautin, 1987, from the Indian Ocean off Western Australia. A distinctive feature of Stylobates is the chitinous carcinoecium it produces; a carcinoecium is a shell-like structure inhabited by a hermit crab. Of anemones that attach to gastropod shells inhabited by hermit crabs, animals of some species (e.g. those belonging to Calliactis) form a thin layer of chitin over the shell. Those of other species (e.g. those belonging to Stylobates and Paracalliactis) cover but extend the shell, producing a carcinoecium. The ability to form a carcinoecium is a convergent attribute of anemones (Gusmão and Daly 2010); anemones possessing this ability belong to four families (Daly et al 2004)

Methods

Results

Discussion

Conclusion