A new species of Bestiolina (Copepoda, Calanoida, Paracalanidae) and complementary description of B. similis (Sewell, 1914) from the Nansei Islands, Japan.

Two species of the calanoid copepod genus Bestiolina occurred in estuarine/coastal waters of the Nansei Islands, southernmost Japan. One of them is described herein as Bestiolina okinawae sp. nov., which is distinguished from known congeners by a combination of the following characteristics: 1) fifth pedigerous somite bearing groups of tiny spinules on the posterior end, 2) female mandible bearing a rod-shaped first gnathal tooth, 3) male left leg 5 with short apical spine on long terminal segment, and 4) legs 23 with endopodal segment 2 lacking spinules. The new species was the dominant zooplankter in oligohaline waters. The other species is morphologically identifiable to Bestiolina similis (Sewell, 1914). Genetic analysis using COI revealed that the two species differed by 9.910.0%, in contrast to small intra-specific genetic variation (0.01.5%). The two species were spatially segregated in low-salinity (230) estuaries and high-salinity (2536) coastal waters, respectively, but co-occurred in some samples. Their body length decreased from the winter (around 20°C) to the summer (around 30°C) by 9.518.1%, depending on the species and sex. In both species, adult males, which lack mandibular gnathobase, were larger than the adult females.

A new species closely related to Acartia sinjiensis (Copepoda: Calanoida), from river estuaries of northern Luzon, the Philippines.

We describe a brackish-water calanoid copepod Acartia (Acanthacartia) cagayanensis sp. nov. collected from river estuaries in the northernmost Luzon, the Philippines. The new species has several characteristic features that are typical to the A. plumosa group (A. (A.) plumosa Scott T., 1894, A. (A.) sinjiensis Mori, 1940 and A. (A.) tropica Ueda Hiromi, 1987); specifically, a short apical spine on the long terminal segment of male left leg 5, which is unique to the group. The morphological features of A. cagayanensis sp. nov. different from those of the A. plumosa group are the barrel-shaped genital double somite and the cylindrical basal part of the terminal segment of female leg 5. Among the species in the group, A. cagayanensis sp. nov. is closest to A. sinjiensis in terms of the spinule patterns on the female antennule, the posterior corner of the prosome, and the male second urosomite. The genetic analysis using DNA sequences of mitochondrial gene cytochrome oxidase subunit I (COI) revealed that A. sinjiensis from Japan and A. cagayanensis sp. nov. differed by 16.5-16.9%, in contrast to a small variation (0.0-0.5%) within each population. We confirmed that previous records of A. sinjiensis from the Philippines were not A. cagayanensis sp. nov., and therefore, A. cagayanensis sp. nov. is the third species of the subgenus Acanthacartia Steuer, 1925, after A. sinjiensis and A. (A.) tsuensis Ito, 1956.

Quellenin, a new anti-Saprolegnia compound isolated from the deep-sea fungus, Aspergillus sp. YK-76.

Saprolegnia parasitica, belonging to oomycetes, is one of virulent pathogen of fishes such as salmon and trout, and causes tremendous damage and losses in commercial aquacultures by saprolegniasis. Previously, malachite green, an effective medicine, had been used to control saprolegniasis. However, this drug has been banned around the world due to its mutagenicity. Therefore, novel anti-saprolegniasis compounds are urgently needed. As a new frontier to discover bioactive compounds, we focused on the deep-sea fungi for the isolation of anti-saprolegniasis compounds. In this paper, on the course of anti-saprolegniasis agents from 546 cultured broths of 91 deep-sea fungal strains, we report a new compound, named quellenin (1) together with three known compounds, diorcinol (2), violaceol-I (3) and violaceol-II (4), from deep-sea fungus Aspergillus sp. YK-76. This strain was isolated from an Osedax sp. annelid, commonly called bone-eating worm, collected at the São Paulo Ridge in off Brazil. Compounds 2, 3 and 4 showed anti-S. parasitica activity. Our results suggest that diorcinol and violaceol analogs and could be good lead candidates for the development of novel agents to prevent saprolegniasis.