The shallow water planktonic shrimp Acetes indicus H. Milne Edwards, 1830 (Crustacea: Decapoda: Sergestoidea) was established on the basis of specimens obtained from the Ganges Delta, and is the type species of the genus Acetes. This shrimp is important as one of the major products for small-scale coastal fisheries across tropical eastern Asia. The results of mitochondrial DNA analyses from individuals across South and South-East Asia have revealed the existence of two genetically separate major clades, one of which could be further divided into two sub-clades, leading to three reciprocally monophyletic clades (Bangladesh, South-East Asia, and eastern Indian Ocean clades). Morphological analysis agreed with the results of genetic analyses by showing minor, but consistent differences between the three clades, demonstrating that they are isolated reproductive units. This finding has raised a concern about the true identity of A. indicus. The type (s) of A. indicus were not found in the most possible holding institution, Muséum national d’Histoire naturelle, Paris (MHHN). Specimens from Bangladesh, possible topotypic materials sampled at different times and locations, were regarded the representative of A. indicus. Accordingly, a new species, Acetes omorii (≈ Omori’s large form), is proposed to accommodate the sister clade occurring in South-East Asia. Moreover, Acetes spiniger Hansen, 1919, once regarded a synonym of A. indicus, is herein re-validated to accommodate the Indian Ocean population (≈ Omori’s small form).

Based on field observations and rearing experiments in Nagano and Niigata prefectures in central Honshu, Japan, we newly describe and illustrate immature stages of the tenthredinid sawfly Togashia horii (Togashi, 1962) and summarize current knowledge on its distribution and life history. The larvae of this species are well characterized by their conspicuous appearance, large size, gregarious feeding behavior and the wood-burrowing behavior on maturity.

Based on material obtained in Malaise traps or yellow pan traps, collection data are given for the following four species of xiphydriid woodwasps: Hyperxiphia hirashimai (Okutani, 1965), Platyxiphydria tiphiiformis Takeuchi, 1938, Xiphydria annulitibia Takeuchi, 1936, and Xiphydria melanoptera Shinohara, Hara and Smith, 2020. Xiphydria annulitibia is newly recorded from Gifu Prefecture. The male of X. melanoptera is described for the first time and the distinction of this species from X. kastsheevi Ermolenko, 1979, is discussed based on the newly acquired material.

A new pufferfish, Torquigener heemstrai is described from five specimens collected at depths of 22–30 m on Tugela Bank off KuaZulu-Natal in South Africa. The new species is distinguished from other species of Torquigener by the following combination of characters: dorsal surface of body from nasal organs to just before dorsal fin covered by spinules; ventral surface of body from level of nasal organs to anus densely covered by spinules; prebranchial margin with 11–14 long spinules; dorsal-fin rays 8–9, anal-fin rays 7, pectoral-fin rays 14, lateral skin fold running behind anal fin to caudal-fin base, dorsal half of body blackish brown with many short white lines, an irregular white line running along ventrolateral part of body just above a skin fold from dorsal end of gill opening to caudal peduncle, and ventral part of body white. A key to the species of Torquigener in South Africa is given.