Multiple ancient origins of neoteny in Lycidae (Coleoptera): consequences for ecology and macroevolution

Neoteny, the maintenance of larval features in sexually mature adults, is a radical way of generating evolutionary novelty through shifts in relative timing of developmental programmes. While controlled by the environment in facultative neotenics, retention of larval features is obligatory in many species of Lycidae (net-winged beetles). They are studied here as an example of how developmental shifts and ecology interact to produce macroevolutionary impacts. We conducted a phylogenetic analysis of Lycidae based on DNA sequences from nuclear (18S and 28S rRNA) and mitochondrial (rrnL, cox1, cob and nad5) genes from a representative set of lineages (73 species), including 17 neotenic taxa. Major changes of basal relationships compared with those implied in the current classification generally supported three independent origins of neotenics in Lycidae. The southeast Asian Lyropaeinae and Ateliinae were in basal positions indicating evolutionary antiquity, also confirmed by molecular clock estimates, unlike the neotropical leptolycines nested within Calopterini and presumably much younger. neotenics exhibit typical K-selected traits including slow development, large body size, high investment in offspring and low dispersal. This correlated with low species richness and restricted ranges of neotenic lineages compared with their sisters. Yet, these factors did not impede the evolutionary persistence of affected lineages, even without reversals to fully metamorphosed forms, contradicting earlier suggestions of recent evolution from dispersive non-neotenics

The family Donacidae (Bivalvia: Tellinoidea) in Thai waters

The species belonging to the family Donacidae living in Thailand waters are herein revised. After an exhaustive bibliographical search, 29 nominal species were found from this area. Materials from several institutions and specimens collected during fieldwork in Phuket and the Gulf of Thailand were studied. All the type materials were illustrated and redescribed. Details of the type localities, repositories, habitats and biogeographical distribution are discussed. In addition, some collected specimens and the type materials of the valid species and synonyms are illustrated. Currently, eight valid species are confirmed as living in Thailand waters: Donax (Deltachion) spinosus Gmelin, 1791, Donax (Deltachion) semigranosus (Dunker, 1877), Donax (Dentilatona) incarnatus Gmelin, 1791, Donax (Hecuba) scortum (Linnaeus, 1758), Donax (Latona) cuneatus Linnaeus, 1758, Donax (Latona) faba Gmelin, 1791, Donax (Latona) solidus Spengler, 1798 and Donax (Paraserrula) introradiatus Reeve, 1855. The presence of Donax (Deltachion) semisulcatus Hanley, 1843, Donax brazieri Smith, 1892, Donax (Tentidonax) veruinus Hedely, 1913 and Donax victoris Fischer-Piette, 1942 in Thailand waters remains uncertain. These species have been reported in the study area in the literature, but they were not sampled during this study.Fil: Signorelli, Javier Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Printrakoon, Cheewarat. Kasetsart University; Tailandi