The establishment of a neotype for Luidia clathrata (Say, 1825) and a new species within the genus Luidia (Asteroidea: Paxillosida: Luidiidae)

摘要

Over approximately 160 years, asteroid literature dealing with Luidia clathrata (Say) has contin-ually overlooked ecological and detailed morphological characters of the very distinct bluish gray single central dark stripe paxillar form that normally lives in an estuarine salinity environment on a substrate of very fine sand mixed with clay ("mud"). In contrast, there is a larger form that has yellow-orange paxillae arranged in rows separated by longitudinal brown stripes outside of the central black stripe. It lives offshore, in higher salinity at depths up to 40+ m on a substrate characterized by sand mixed with shell hash. In addition to living color differences, there are morphological differences such as paxillar counts enclosed in a one cm width of the dorsal side the arm located approximately 25% of the inner length of the arm (L. clathrata = mean count of 214.7/cm; Std. dev. = 29.2/cm; L. n. sp. = mean count of 166.2/cm; std. dev. 21.8/cm. The difference is significant at P= ≤0.001). There are additional morphological differences. In addition to ecological distribution, color, and orphological differences, analytical molecular differences have been determined by electrophoresis of isozyme oteins and DNA sequencing. The holotype of Luidia clathrata (Say) has never been found. We have selected SNM 8507 as the neotype. The holotype for the new species of Luidia is USNM 6923.