The distribution and some features of the biology of the ghost shrimp Nihonotrypaea japonica (Ortmann, 1891) (Decapoda: Callianassidae) from the Volchanka River estuary (Vostok Bay, Sea of Japan)

Abstract

In August and October of 2013, the patterns of the spatial distribution, size, and sex composition of the estuarine population of the ghost shrimp Nihonotrypaea japonica were studied in the Vostok Bay (Peter the Great Bay, Sea of Japan) for the first time in Russian waters. It was found that this species inhabits waters under monthly mean temperatures from -1.6 to 21.7°C and salinity from 11.2 to 32.5‰, populating silted sand below the ice cover that is typical for December-March. The maximum population density of N. japon ica reached almost 200 ind./m 2 , and a biomass of 120 g/m 2 with average values of these parameters of 18 ± 43 ind./m 2 and 10.83 ± 25.50 g/m 2 , respectively, which is almost one third of the total biomass of the macro zoobenthos. The population consisted of males with body lengths of 14-61 mm and females from 17 to 58 mm. In the size composition four groups of individuals were distinguished: underyearlings, 1 , 2 , and, apparently, 3 year old animals. The male/female ratio is close to 1 : 1.2. Males prevailed in animals with body lengths of less than 20 mm, while females prevailed among larger individuals. Features of the spatial distribu tion, size, and sex composition of populations of N. japonica are discussed in relation to the environment and reproduction at the northern boundary of its range.

Features of the spatial distribution of the Japanese mud shrimp Upogebia major (De Haan, 1841) (Decapoda: Upogebiidae) in the Vostok Bay, Sea of Japan

“…As a result, new species have been revealed in the fauna of the region [8,21]; for a number of animals known from single finds, the real abundance estimates were obtained for the first time, the features of the spatial distribution and biology of reproduction were defined, and population parameters were given [10][11][12].…”

“…The abundance of mud shrimp was assessed by two techniques that are used in the study of burrowing crustaceans [12,20,23]. Following the first mode, five transects were laid, from the shore to a depth of 3 m at a distance of 140 m from each other crossing the areas of coastal silted sand bottom and the eelgrass Zostera marina distribution.…”

A Microsporidian Infection in Phoronids (Phylum Phoronida): Microsporidium phoronidi n. sp. from a Phoronis embryolabi

“…Adult phoronids live as commensals in the burrows of the shrimp Nihonotrypaea japonica . These shrimps make borrows at shallows, in a substratum composed of silt and sand (Selin ). Burrow holes are located at the depth of 60 cm and are well visible under water (Fig.…”

The Stable Carbon and Nitrogen Isotope Compositions of Larvae of Burrowing Shrimps (Crustacea: Decapoda: Gebiidea and Axiidea) from Vostok Bay, Sea of Japan

“…When burrowing, they bioturbate sediment, changing its structure and increasing the rate of degradation of organic substances [13, 17, 28, 47, etc.]. Many of them form aggregations with significant densities, which, e.g., in the callianassids Nihonotrypaea harmandi and N. japonica off the coast of Japan reached 1440 and 340 ind./m 2 , respectively [27]; in Russian waters, a density of about 200 ind./m 2 was reported for N. japonica [9]. These are quite large animals with high fecundity.…”