Echinoderes rex n. sp. (Kinorhyncha: Cyclorhagida), the largest Echinoderes species found so far

Abstract

A new kinorhynch species, Echinoderes rex n. sp., is described from the Korea Strait. The new species is characterized by a pair of diminutive lateral terminal spines (19-23 mu m) and a trunk length of 482-528 mu m, making it the largest Echinoderes described so far. Unique for the new species is also the presence of a type of putative glandular cell outlets that have not been described previously. This paper presents light and scanning electron micrographs of the new structure. In addition, E. rex n. sp. is characterized by having a single middorsal spine on segment 4, lateroventral tubules on segment 5 and 8 and lateroventral acicular spines on segments 6 and 7. A pair of distinct and conspicuously large sieve plates, only described from two other species of the genus, is present on segment 9 in E. rex n. sp. A comparison is made with other species of Echinoderes and the similarities are discussed.