Nucleotide sequence of the vmhA gene encoding hemolysin from Vibrio mimicus

AbstractThe structural gene (vmhA) of hemolysin from Vibrio mimicus (ATCC33653) was cloned and sequenced. The vmhA gene contains an open reading frame consisting of 2232 nucleotides which can code for a protein of 744 amino acids with a predicted molecular mass of 83 059. The similarity of amino acid sequence shows 81.6% identity with Vibrio cholerae El Tor hemolysin

Seasonal variations and trophic relationships among concentrated populations of small fishes in seagrass meadows

Temporal and experimental changes in populations of potential competitors, their resources used, and their available resources can illustrate periods of competition. Dense populations and foods of small fishes were analyzed during 1982-1983 for day-night and monthly changes in an assemblage concentrated naturally in seagrass meadows of Redfish Bay, Texas. Samples totalled 10,223 fishes, in 23 families and 40 species. Fish densities averaged 15.1/m² in shoalgrass and 6.2 individuals/m² in turtlegrass meadows, which were somewhat deeper. The darter goby, pinfish, code goby, and Gulf pipefish were the most common fish species in both shoalgrass and turtlegrass meadows throughout the year. The darter goby predominated in shoalgrass, while the pinfish and code goby predominated in turtlegrass meadows. No clear day-night differences in densities of each common fish were detected during most of the year. Peak abundance of total fishes occurred during spring, with a secondary peak in fall and a minimum in winter. Each of the four common species showed its own seasonal abundance pattern, and had a different larval recruitment and peak abundance separated 1-3 months from other species, with some overlap. Seasonal feeding data for the four most abundant fish species were compared with respect to prey availability to illustrate how resource partitioning of food could mediate possible competition among these abundant consumers. When prey (mainly amphipods) were abundant, during spring, many fish species showed high overlap in food use. Regardless of food availability, the code goby and Gulf pipefish fed mainly on amphipods and copepods. The more common darter goby and pinfish were carnivorous during spring, but they showed herbivorous feeding habits during summer, when they consumed mainly epiphytic algae during periods of lower prey availability. These changes in resource use also resulted during depletion of major foods by fishes concentrated experimentally in cages. These shifts in diets reflect a temporary partitioning of available foods. Different seasonal abundance patterns with different times of peak recruitment among seagrass fish species thus seem to permit use of the seagrass meadow habitats with reduced, seasonal competition for major foods among these concentrated fishesEcology, Evolution and Behavio

Epibenthic invertebrate fauna in the southern coast of the East Sea, Korea

This study surveyed epibenthic invertebrate fauna in the southern coast of the East Sea, Korea. Benthic invertebrate samples were collected seasonally between 2005 and 2008 using a demersal trawl. In total, 76 invertebrate species belonging to six phyla (Cnidaria, Sipuncula, Mollusca, Annelida, Arthropoda, and Echinodermata) were collected for the study, with four species being added to the International Union for Conservation of Nature Red List of Threatened Species. The number of species, abundance, species diversity, richness, and evenness varied with season. The peaks in the species number and abundance were recorded in spring and summer, whereas the catch rates were relatively low in autumn and winter. Species diversity, richness, and evenness tended to be low in summer than other seasons

Length–weight relations for 29 demersal fishes caught by small otter trawl on the south-eastern coast of Korea

We present herewith the relations between total length and weight (LWRs) for 29 fish species from the southern coast of the East Sea (=Sea of Japan), Korea: Conger myriaster (Brevoort, 1856); Coilia nasus Temminck et Schlegel, 1846; Engraulis japonicus Temminck et Schlegel, 1846; Clupea pallasii pallasii Valenciennes, 1847; Coelorinchus multispinulosus Katayama, 1942; Lophius litulon (Jordan, 1902); Zeus faber Linnaeus, 1758; Paracentropogon rubripinnis (Temminck et Schlegel, 1843); Lepidotrigla guentheri Hilgendorf, 1879; Liparis tanakae (Gilbert et Burke, 1912); Acropoma japonicum Günther, 1859; Doederleinia berycoides (Hilgendorf, 1879); Jaydia lineata (Temminck et Schlegel, 1842); Ostorhinchus semilineatus (Temminck et Schlegel, 1842); Sillago sihama (Forsskål, 1775); Trachurus japonicus (Temminck et Schlegel, 1844); Pagrus major (Temminck et Schlegel, 1843); Pennahia argentata (Houttuyn, 1782); Zoarces gillii Jordan et Starks, 1905; Callionymus lunatus Temminck et Schlegel, 1845; Callionymus valenciennei Temminck et Schlegel, 1845; Amblychaeturichthys hexanema (Bleeker, 1853); Amblychaeturichthys sciistius (Jordan et Snyder, 1901); Sphyraena pinguis Günther, 1874; Trichiurus lepturus Linnaeus, 1758; Psenopsis anomala (Temminck et Schlegel, 1844); Pseudorhombus pentophthalmus Günther, 1862; Pseudopleuronectes yokohamae (Günther, 1877); and Cynoglossus robustus Günther, 1873. The LWRs for 12 species are estimated for the first time and new maximum lengths for six species are reported herewith. All of the relations between total length and weight were significant (all r² > 0.938). The values of exponent b, estimated using simple linear least squares of log-transformed weight and length data, ranged from 2.730 to 3.440.5 page(s

Dietary habits and feeding strategy of the fivespot flounder, Pseudorhombus pentophthalmus in the southeastern coast of Korea

The dietary habits and feeding strategy of Pseudorhombus pentophthalmus were studied based on 484 specimens collected from January to December 2006 off the southeastern coast of Korea. The total length (TL) of the specimens was 8.6–26.8 cm. P. pentophthalmus is a bottom-feeding carnivore that primarily consumes caridean shrimps and secondarily consumes teleosts, but also eats small amounts of crabs, cephalopods, mysids, euphausiids, stomatopods, amphipods, copepods, and isopods. The dietary compositions of P. pentophthalmus significantly differed between size groups during summer, but did not differ between size groups during other seasons, with caridean shrimps dominating the diet of both small and large groups in spring, autumn and winter. Permutational multivariate analysis of variance (PERMANOVA) and analysis of similarities (ANOSIM) revealed significant dietary differences by season, but not by size. Graphical analysis indicated that all size groups of P. pentophthalmus consumed mainly caridean shrimps during all seasons, but teleosts were only important during summer.11 page(s

Temporal variations of fish assemblage in the surf zone of the Nakdong River Estuary, southeastern Korea

To assess temporal variations in fish assemblages, fish samples were collected on a monthly basis in the surf zone of the Nakdong River Estuary in 2004. Surveys were conducted at two sites during day and night neap tides using a 10-m beach seine. In total, 2397 specimens (8146.0 g) comprising 27 species and 16 families were collected during the study period. The dominant fish species were Mugil cephalus, Plecoglossus altivelis, Favonigobius gymnauchen, Opsariichthys uncirostris amurensis, and Hyporhamphus sajori, which accounted for 84.6% of the total number of individuals. The fish sampled were primarily small species or the early juveniles of larger species. The species composition and abundance varied greatly, with a peak in the number of individuals in July (summer) and January (winter), and the peak in biomass during July (summer). The catch rate was low in the spring and autumn months due to the low abundance of the dominant species recorded. A cluster analysis revealed that the fish assemblages were characterized by distinct seasonal groups reflecting the reproductive habits of adult fishes. Fish abundance did not significantly differ between the two sites, although a significant difference in their abundance was detected between day and night, with more fish specimens collected at night than during the day at both sites. The Nakdong River Estuary is an important ecosystem for small and/or juvenile fishes, providing a habitat within the estuary suitable for their development and migration.9 page(s

Diet composition in summer of rosefish Helicolenus hilgendorfii on the southeastern coast of Korea

The feeding habits of Helicolenus hilgendorfii were studied using 93 specimens (35-135 mm in standard length) collected from the southeastern coast of Korea during the summer season (June-August) from 2005 to 2007. Helicolenus hilgendorfii is a carnivore that mainly consumes shrimps and fishes. Its diet also includes small quantities of mysids, amphipods, euphausiids, copepods, and isopods. Our graphical method for feeding habits revealed that H. hilgendorfii is an opportunistic and specialized predator on shrimps, especially Crangon hakodatei, although H. hilgendorfii showed an ontogenetic dietary shift, the proportion of shrimp decreasing and the consumption of fishes gradually increasing with the increase of fish size.5 page(s

Feeding habits of Kammal thryssa Thryssa kammalensis (Bleeker, 1849) in the coastal waters of Gadeok-do, Korea

The feeding habits of Thryssa kammalensis was studied using 430 specimens collected from October 2010 to September 2011 in the coastal waters of Gadeok-do, Korea. T. kammalensis in the coastal waters of Gadeok-do was carnivorous predator and planktonic feeder with a wide variety of prey items such as arrowworm, copepods, crab larvae, shrimp larvae, and fish eggs. In addition, T. kammalensis consumed mainly arrowworm, copepods, crab larvae, shrimp larvae, fish eggs, and the diet also included small quantities of cladocerans, amphipods, bivalve larvae, mysids, and euphausiids. On the other hand, the body length (BL) of T. kammalensis specimens ranged from 5.9 to 15.1 cm. Size-related variations in dietary composition of T. kammalensis were not significant that overlap indexes of each major food items that showed very high values in all size classes, representing more than 0.80. Arrowworms were the dominant prey item in all sizes, and copepods were the next most frequent prey item consumed in all size classes. Seasonal changes in dietary composition of T. kammalensis were significant. However, overlap indexes of each major food items in some season showed very high values of 0.80 (between spring and winter) and 0.85 (between summer and autumn). Copepods were most frequently eaten in the spring and winter. Moreover, arrowworm were the dominant prey item in summer and autumn. Mean numbers of prey per stomach (mN/ST) changed significantly with size groups (P 0.05).6 page(s