Two new species of Echiura from Madagascar with a note on the male of Metabonellia hasweilli

Volume: 403Start Page: 1039End Page: 104

A new viviparous species of asterinid (Echinodermata, Asteroidea, Asterinidae) and a new genus to accommodate the species of pantropical exiguoid sea stars

This paper describes a new species of viviparous, intragonadal brooder of asterinid sea star and clarifies the identities of Patiriella pseudoexigua Dartnall 1971, the species Patiriella pseudoexigua sensu Chen and Chen (1992) and Patiriella pseudoexigua pacifica (Hayashi, 1977). The latter is raised to specific rank. Analysis of mitochondrial DNA supports the concept of a pan-tropical assemblage of species for which a new genus, Cryptasterina, is created. All species in Cryptasterina are morphologically similar and comprise species with planktonic, lecithotrophic, non-feeding larvae, and viviparous outlier species with limited distributions. The full diversity of this species diaspora remains to be resolved

Morphological and genetic variation indicate cryptic species within Lamarck’s little sea star, Parvulastra (=Patiriella) exigua

The asterinid sea star Parvulastra exigua (Lamarck) is a common member of temperate intertidal marine communities from geographically widespread sites around the southern hemisphere. Individuals from Australian populations lay benthic egg masses (through orally directed gonopores) from which nonplanktonic offspring hatch and metamorphose without a dispersing planktonic larval phase. Scattered reports in the taxonomic literature refer to a similar form in southern Africa with aborally directed gonopores (and possibly broadcast spawning of planktonic eggs and larvae); such differences would be consistent with cryptic species variation. Surveys of morphology and mtDNA sequences have revealed cryptic species diversity in other asterinid genera. Here we summarize the taxonomic history of Lamarck’s "Astérie exiguë" and survey morphological variation (the location of the gonopores) for evidence that some P. exigua populations include cryptic species with a different mode of reproduction. We found strong evidence for multiple species in the form of two phenotypes and modes of reproduction (oral and aboral gonopore locations) in populations from southern Africa and islands in the Atlantic and Indian oceans. Both modes of reproduction have broad geographic ranges. These results are consistent with previously published genetic data that indicate multiple species in African and island (but not Australian) populations