Shallow water sponges settled on a raft along the Pong River (Lower Mekong Basin, Thailand) were investigated to highlight the taxonomic richness, composition, relative abundance and lifestyle of sponge-dwelling aquatic Insecta. The three-dimensional biogenic structures of the model sponges hosted 4 orders of Insecta, belonging to 10 families and 19 genera/species, able to strictly coexist at the level of the sponges in aquiferous canals and/or at the body surface, and/or dwelling in the extracellular matrix. On the basis of the identified 379 larvae and pupae, Trichoptera and Diptera were found to be the dominant inhabitants of Corvospongilla siamensis (Demospongiae: Spongillida), endemic to Southeast Asia. In the focused lotic ecosystem, dominated by soft bottoms, sponges play a functional role. Insecta use sponges as a substratum, nursery ground, food source, and shelter microhabitat, protecting them from predation and environmental aggression. Moreover, their feeding behavior indicates the insects’ adaptive traits to recycle sponge siliceous spicules as a source of exogenous material to strengthen the larval–pupal cases and the digestive system. The results of the Thai sponge model contribute to the inventory of global engineering species richness, ecosystem types, and biogeographic diversity, thus raising awareness for freshwater biodiversity conservation. In this regard, the present data, along with the worldwide inventory, focus on sponges as (a) key habitat-forming species for aquatic insect assemblages, (b) ecosystem engineers in river/lake/wetland ecosystems, providing water purification, the processing of organic matter, recycling of nutrients, and freshwater–terrestrial coupling, and (c) promising candidates in restoration projects of tropical freshwater ecosystems by bioremediation.

A new occurrence of the genus Corvospongilla (Porifera: Demospongiae) is recorded from the Southeast Asia freshwater of Khorat Plateau, northeast Thailand. This is the second record of the genus from the Lower Mekong Basin with the discovery the new species Corvospongilla lampaoensis sp. nov. inhabiting a eutrophic lentic habitat (in Lam Pao Reservoir) on manmade structures of fish farming and fishery. Skeleton and gemmules morphotraits, diagnostic for Genus Corvospongilla of the family Spongillidae (Order Spongillida), were examined by Light and Scanning Electron Microscopy differentiating a new species from its twenty congeners known worldwide. In addition, the comparative morpho-analysis highlighted distant sympatric lineages with a notable morphotraits divergence of Corvospongilla lampaoensis sp. nov. vs Corvospongilla siamensis in two western tributaries of the Lower Mekong. The results from this study expand our knowledge of the order Spongillida adaptive radiation in Asia and fill a gap in the geographic range of the genus Corvospongilla in the Oriental-Indomalayan Region.

Faunistic investigations on freshwater bodies of the Bangkok Metropolitan Area resulted in the discovery of a freshwater sponge population fragmented in small lentic microhabitats at the Suan Luang Rama IX Park. Sponges living in the lotus and waterlily garden and tropical greenhouse were photographed in situ, and some representative, small samples were collected and stored at the Division of Biology (Porifera Collection), Rajamangala University of Technology Krungthep, Bangkok. The taxonomic integrative analyses focused on diagnostic morphotraits, barcoding, and biogeography. The sponge population was ascribed to Radiospongilla cf. cerebellata (Porifera: Demospongiae: Spongillida: Spongillidae) and is a new record for the Bangkok area and the entire Thai inland water. Comparative integrative analyses vs spongillid taxa worldwide resulted in the discovery of new gemmular morphotraits for the genus. Although the Thai Radiospongilla cf. cerebellata diverges from the Indian type of Radiospongilla cerebellata at the level of gemmular theca architecture, molecular analyses highlighted the matching of the former with the Radiospongilla cluster. A possible allochthonous origin of the Bangkok Radiospongillas population is hypothesised. This investigation on botanical gardens aquatic fauna and a review of appropriate literature highlights that sponges are able to inhabit very confined and fragmented, shallow water bodies, i.e., scattered terracotta pots, plastic containers, and small ponds with aquatic plants also in megalopolis gardens.