Octocorais (Cnidaria: Anthozoa) da coleção de cnidaria do Laboratório de Invertebrados Marinhos do Ceará (LIMCE)

Abstract

Cnidaria is a marine invertebrates group of great morphological diversity, life cycles, ecology and development. The five classes within the group, Hydrozoa, Anthozoa, Cubozoa, Scyphozoa and Staurozoa, are united by the presence of structures called cnida. The Anthozoa class is composed by two large groups, Hexacorallia and Octocorallia. Octocorallia are morphologically well-defined invertebrates, with the vast majority of species being colonial and the autapomorphy is the presence of eight tentacles and eight complete mesenteries in their polyps. The presence of sclerites, microscopic calcareous structures of ectodermal origin, are among the main characters used in the taxonomy of Octocorallia. The specimens were collected by individual projects and collections, carried out in the years 1990 to 2013. The methods for collecting the specimens ranged from scuba diving with SCUBA equipment to manual collection of tides. All batches containing octocorals had no identification, thus new labels were made and numbers of tumbles added. For identifications inside the group, both macroscopic and microscopic characters were observed, and it was necessary to prepare slides for observation in optic microscopy and scanning electron microscopy (SEM) for sclerite analysis. Other characteristics as shape of the colony, height, branches and calyces were also observed and measured. The goal of the study was to identify the octocorals and to perform an annotated checklist of the specimens from the scientific collection of Cnidaria of the Marine Invertebrate Laboratory of Ceará (LIMCE). The 24 specimens were identified into two orders within the subclass Octocorallia: Pennatulacea and Alcyonacea. For the order Pennatulacea all lots are inserted in the family Renillidae and for the genus Renilla. For the order Alcyonacea the diversity was greater with representatives of the families Acanthogorgiidae, Ellisellidae, Clavularidae, Gorgoniidae, and Plexauridae. The lots were identified at the lower taxonomic level with the exception of Thesea sp. and Leptogorgia sp., which were not possible due to the conservation status of the materials. Some lots represented the first registry for the state of Ceará, such as Renilla köellikeri, Renilla reniformis, Acanthogorgia schrammi, Leptogorgia hebes and Plexaurella dichotoma. The lack of specialist for the state reflects on the low number of species known when compared to the Caribbean.