Biodiversity assessment of the Lower Mekong Basin: A new species of Corvospongilla (Porifera: Spongillina: Spongillidae) from Thailand

Only six species (four genera, one family) of freshwater sponges are known until now from Thailand. A first record of the genus Corvospongilla Annandale, 1911 with the description of a new species is here reported from the Pong River in the Lower Mekong Basin. The taxonomic status of Corvospongilla siamensis nov. sp. is discussed in comparison to the 18 species assigned to the genus. The new species is characterised by i) alveolate, paucispicular skeletal network with scanty spongin, thick ascending tracts towards the sponge surface to support conules; ii) skeleton of stout microspined strongyles, and extremely rare, abruptly pointed oxeas usually with a few tubercles, plus micropseudobirotules with smooth shaft; iii) gemmules belonging to a single gemmular morph, typically sessile; iv) gemmular cage notably stout, of tangentially arranged strongyles of variable length from tubercled to spiny; v) gemmular theca with abundant laminar compact spongin, lacking pneumatic layer, armed by short, tubercled to spiny strongyles tangentially embedded; vi) larvae armed by spiny oxeas. Corvospongilla siamensis nov. sp. differs from all the other known species of the genus in its unique combination of diagnostic traits, particularly a) acanthostrongyles (megascleres), b) gemmuloscleres, both in the cage and in the theca, as strongyles showing the tendency towards ring-shape and button-like shape, and c) larval spiny oxeas

Biodiversity assessment in the Lower Mekong basin: First record of the genus Oncosclera (Porifera: Spongillina: Potamolepidae) from the Oriental Region

Taxonomic richness of Thai Spongillina numbers so far seven species (five genera, one family). The first record of the genus Oncosclera Volkmer-Ribeiro, 1970 belonging to the family Potamolepidae Brien, 1967 is here reported with the description of a new species from the Pong River (NE Thailand, Oriental Region) in the framework of a biodiversity assessment in the Lower Mekong Basin. An emended diagnosis of the genus is also provided. The new species, ascribed to the genus Oncosclera for diagnostic traits of the skeleton and the gemmular architecture, differs from all the other known species of the genus in its unique combination of diagnostic traits. O. asiatica sp. nov. is characterised by i) more or less alveolate skeleton, ii) conulose surface with a network of branched subdermal canals, iii) acanthoxeas as dominant megascleres and less frequent acanthostrongyles, iv) gemmular theca sublaminar of compact spongin with a scantly developed pneumatic layer of fibrous spongin, and v) gemmuloscleres as acanthostrongyles from elongated to ovoid with tubercles/spines particularly dense towards the tips. Despite the extremely disjunct distribution O. asiatica is morphologically similar to O. intermedia and O. jewelli from the Neotropical Region and O. gilsoni from Pacific Islands, from which the former diverges for megascleres and/or gemmuloscleres traits

Biodiversity in South East Asia: An overview of freshwater sponges (Porifera: Demospongiae: Spongillina)

Despite the fact that South East (SE) Asia is considered as a biodiversity hotspot, knowledge of sessile invertebrates such as freshwater sponges (Porifera: Haplosclerida: Spongillina) in this region is poor and scarcely reported. For this synopsis, diversity and distribution of SE Asian inland water sponges is reported on the basis of available literature and a recent biodiversity assessment of the Lower Mekong basin. A diagnostic key of families/genera from SE Asia is provided together with Light Microscopy and Scanning Electron Microscopy protocols to prepare the basic spicular complement for taxonomic identification. So far, SE Asian freshwater sponges consist of widespread and/or endemic species belonging to the families Metaniidae, Potamolepidae, and Spongillidae. The highest diversity is recorded from Indonesia, Philippines, Thailand, and Myanmar, respectively. Data from the other countries are necessary for our understanding of their diversity and distribution. Biodiversity in SE Asia is strongly underestimated, as indicated by recent new records and the discovery of new species of freshwater sponges in Thailand. Further investigations should reveal higher values of taxonomic richness, highlighting biogeographic patterns at the family/genus/species levels. A cooperative network involving Thai, Laotian and Italian researchers, was set up to contribute and fulfil knowledge on taxonomy, ecology and biotechnological potentialities of these neglected filter feeders, playing a key role in water purification and biomass production in both lentic and lotic ecosystems in the tropics

Biodiversity in South East Asia: An overview of freshwater sponges (Porifera: Demospongiae: Spongillina)

Despite the fact that South East (SE) Asia is considered as a biodiversity hotspot, knowledge of sessile invertebrates such as freshwater sponges (Porifera: Haplosclerida: Spongillina) in this region is poor and scarcely reported. For this synopsis, diversity and distribution of SE Asian inland water sponges is reported on the basis of available literature and a recent biodiversity assessment of the Lower Mekong basin. A diagnostic key of families/genera from SE Asia is provided together with Light Microscopy and Scanning Electron Microscopy protocols to prepare the basic spicular complement for taxonomic identification. So far, SE Asian freshwater sponges consist of widespread and/or endemic species belonging to the families Metaniidae, Potamolepidae, and Spongillidae. The highest diversity is recorded from Indonesia, Philippines, Thailand, and Myanmar, respectively. Data from the other countries are necessary for our understanding of their diversity and distribution. Biodiversity in SE Asia is strongly underestimated, as indicated by recent new records and the discovery of new species of freshwater sponges in Thailand. Further investigations should reveal higher values of taxonomic richness, highlighting biogeographic patterns at the family/genus/species levels. A cooperative network involving Thai, Laotian and Italian researchers, was set up to contribute and fulfil knowledge on taxonomy, ecology and biotechnological potentialities of these neglected filter feeders, playing a key role in water purification and biomass production in both lentic and lotic ecosystems in the tropics