Three terrestrial species of Bryodrilus, a genus never recorded before in China, are described from Mt. Changbaishan, Jilin Province, north-eastern region of China. Bryodrilus longifistulatus sp. nov. is diagnosed by having 3-5 chaetae per bundle, an anterior convexity of the brain, a long sperm funnel, and numerous large spermathecal ectal glands ; B. macrotheca sp. nov. is characterized by the presence of 6-8 spermathecal diverticula, bilobed penial bulbs, and an unpaired seminal vesicle. Bryodrilus parvus Nurminen, 1970 is recorded from the country for the first time.
An echiniscid tardigrade, Echiniscus hoonsooi Moon and Kim, previously known only from South Korea, is reported from central Japan. A redescription, illustrations, and light and scanning electron photomicrographs are provided. Special attention is given to the intraspecific variability in the body cirri, and discriminating points from some similar species are also discussed.
Acarochelopodia biunguis Bartsch, 1988 and four new species of Actacarus (A. chelonis, A. cornutus, A. nanus, A. spinosus) are recorded from beaches and subtidal sediments of northeastern Australia ; A. spinosus and A. chelonis are also recorded from French Polynesia, and the latter species from Indonesia. Specimens from Western Australia, previously referred to as Actacarus pacificus Bartsch, 1979, are described as Actacarus marindicus sp. nov., A. orthotectus Newell, 1984 is removed from synonymy with A. pacificus, and Japanese records of A. pacificus are commented on. A key to the Australian species of Actacarus is presented.
A new species of Heteromysis is described from a blue hole on Grand Bahama Island. It is distinguished by having a single inner spine on the uropod endopod, 9 to 10 uniformly distributed spines on the lateral margins of the telson, and spination of the whole distal emargination of the telson. Modified setae distally on the third segment of the peduncle of the first antenna, as characteristic of the subgenus Olivaemysis, are present only in the female, while the male pleopods are typical of the subgenus Heteromysis.
Seventy-two specimens representing two new species of Alvinocaris of the family Alvinocarididae, A. brevitelsonis and A. leurokolos, were found in samples collected from thermally influenced fields at the Minami-Ensei Knoll (28°23.35'N, 127°38.38'E, 705m depth). The shrimps appeared to be the co-dominant macroinvertebrates in the small hollows of chimneys and among the mussel beds, bathing directly in vent fluids in the high temperature hydrothermal field. A key to the seven known species of Alvinocaris is given.
Spawning of Luidia foliolata in Barkley Sound, British Columbia, Canada, occurs in spring. Ova are transparent and about 150μm in diameter. The first cleavage occurs approximately 3hr after fertilization at ca. 10℃. The embryo develops into a bipinnaria after a wrinkled blastula stage. Metamorphosis takes place about 4 mo after fertilization, without the larva's passing through a brachiolaria stage. The full-grown bipinnaria is 2.5mm long and has five pairs of bipinnaria arms. At metamorphosis the larval part is absorbed into the asteroid rudiment. Juveniles are about 730μm in diameter. They have five arms, each bearing two pairs of tube-feet. The present observations show that L. foliolata undergoes a non-brachiolarian type of development, as do all species of Luidia previously studied.
Genetic differences between two widely sympatric and morphologically similar labrid species from the southern coasts of Japan, Pseudolabrus eoethinus (Richardson, 1846) and P. sieboldi Mabuchi and Nakabo, 1997, were investigated by examination of partial sequences of the mitochondrially-encoded 16S rRNA gene. For each species, 15 individuals representing three populations were sequenced. Among the individuals of P. eoethinus, only one showed evidence of a sequence difference, whereas nine haplotypes were found for P. sieboldi. Phylogenetic analyses using maximum parsimony and neighbor-joining methods, with a haplotype of Notolabrus gymnogenis (Gunther, 1862) as an outgroup, showed that the haplotypes of the two species of Pseudolabrus are reciprocally monophyletic. Sequence differences between the haplotypes of the two species ranged from 2.9% to 4.2% (3.3% on average), such being comparable to those among the three congeneric species Pseudolabrus guentheri Bleeker, 1862, P. miles (Bloch and Schneider, 1801), and P. biserialis (Klunzinger, 1879) (2.9-3.6%); furthermore, these differences corroborate the specific status of both of the species from Japan.