Crinoidea da região Nordeste do Brasil e variações intraespecíficas de C. echinoptera e T. carinata

Abstract

The echinoderms (gr. echinos, thorn; + derma, skin) are the symbol of marine life, with approximately 7,000 living species. They are briefly defined as having a calcium carbonate skeleton in the form of calcite; an aquifer vascular system that helps in locomotion, capture of food, among other functions, in addition to presenting pentarradial symmetry in adults. The Crinoidea class is composed of sea lilies and comatulides with about 650 living species and 6,000 fossil species. They are subdivided into pedunculated and non-pedunculated. The aim of the present study was to analyze and characterize the species of Crinoidea from the Northeast, including intraspecific variations of the species Comactinia echinoptera and Tropiometra carinata, providing detailed descriptions, distribution and habitat data of the species, figures of the maintaxonomic characters, in order to expand and update information about these taxa. Therefore, the identification and morphological and morphometric analysis of the Crinoidea specimens registered in the Paulo Young Invertebrate Collection was carried out. 74 specimens were analyzed in the order Comatulida, in the families Comatulidae and Tropiometridae, totaling 4 species: Tropiometra carinata, Comactinia echinoptera, Comactinia sp., e Neocomatellapulchella. Tropiometra carinata presented five characters that vary along the growth stages ofthe species. In Comactinia echinoptera, three characters showed greater variation. Regarding the characters normally used in the identification of the group, we verified that not all charactersare equally consistent when correlated with their respective stages of development. Cirrus and centrodorsal characters are important to differentiate ontogenetic stages, but they proved to be inefficient to separate the studied species. This work expands the knowledge about Crinoidea in Brazil, and reinforces the need for more research focused on this group, in order to understand their taxonomy, biology, ecology, and distribution, as well as the state of their populations along the Brazilian coast.