For over 150 years, ecologists have been striving to explain fundamental patterns of biological diversity, such as the observation that communities invariably consist of common and rare species, and to unravel the processes that underpin these patterns. This task is increasingly urgent given the accelerating loss of biological diversity. Although fishes are the most diverse vertebrate taxon and fish communities occur in a wide range of habitats, they have been relatively little studied in the quest to elucidate the processes that shape patterns of biological diversity. Here, some of the topics that investigations of fish assemblages can illuminate are highlighted. These include the characteristics of ecological communities and the role that dispersal limitation plays in structuring them, the distinction between core and occasional species, the insights that evaluating abundance in different currencies can bring and the assessment of community capacity. Questions are identified that future investigations of fish communities might tackle and a case study of a biodiverse ecoregion (Thailand and Peninsula Malaysia) is used to illustrate the need for better links between these ecological questions and effective conservation practice.

Thailand has a great diversity of ant fauna as a zoogeographical crossroads and biodiversity hotspot. The last publication presenting a Thai ant checklist was published in 2005. In the present paper, based on an examination of museum specimens and published records, a comprehensive and critical species list of Thai ants is synthesized. Currently, 529 valid species and subspecies in 109 genera among ten subfamilies are known from Thailand with their diversity and distribution within 77 provinces presented and assigned to six geographical regions. Furthermore, Thailand is the type locality for 81 ant species. Forty-one species are here newly recorded for Thailand with photographs illustrating these species. The checklist provides information on distribution and a comprehensive bibliography. This study will also serve as a guide for the upper northeast and central Thailand, which are poorly sampled; a comprehensive reference list relating to endemic taxa and localities where conservation is an important priority, thus an essential resource for policy makers and conservation planners concerned with the management of insect diversity in Thailand; and a list of exotic ant species found in Thailand, which could possibly impact the ecological balance.

The acorn barnacle is a sessile crustacean, inhabiting the intertidal areas of tropical and temperate regions worldwide. According to current practices on Cirripedia morphology, shell, opercular valves, and arthropodal characters including cirri and mouthparts are used as a tool for taxonomic classification, and using these characteristics the present study aimed to provide better resolution for the barnacle diversity and geographical distribution within coastlines of Thailand: the Andaman Sea and the Gulf of Thailand.

A new species of the rarely collected ant genus Platythyrea Roger, 1863 closely related to Platythyrea clypeata Forel, 1911 is described and illustrated based on the worker caste under the name Platythyrea janyai sp. n. This species is distributed in southern Thailand and western Malaysia, while P. clypeata is distributed in Sri Lanka, Vietnam, Laos, and Thailand in the areas north of the Isthmus of Kra. Platythyrea clypeata is newly recorded from Thailand from dead wood on the forest floor. The type series of P. janyai was also collected from rotten wood on the forest floor.

In this present study, distantly related acorn barnacle species in the subfamily Newmanellinae (Cirripedia, Thoracica, Tetraclitidae), including Neonrosellavitiata (Darwin, 1854) and Newmanellaspinosus Chan & Cheang, 2016, were discovered in the Andaman Sea of Thailand. Neo.vitiata can be readily distinguished from other newmanellids by shell plate and operculum morphology (external shell, tergum geometry, and pattern of parietal tube) and arthropodal characters (presence of basi-dorsal point at base of penis and triangular spines on cirri, setal type, and mouth parts). Both species were found to share overlapping territories on rocks at the rockweed zone, an area submerged under seawater most of the time throughout the year. This study highlights the first discovery of Neonrosella in the eastern Indian Ocean, whose ultrastructure compared to Newmanella is redescribed and illustrated here based on scanning electron microscopy.