Jae Mook Jeong

The phylogenetic study on Thelohanellus species (Myxosporea) in relation to host specificity and infection site tropism.

Thelohanellus kitauei (Myxobolidae) infects cyprinid fish. The evolution of species derived from common ancestors results in the sharing of biological features. To reveal the origin of T. kitauei biological features, the correlation between phylogeny and biological features of Myxobolidae was investigated by Bayesian inference tree and Bayesian tip association significance testing. The results demonstrated that host specificity and infection site tropism were correlated with the phylogeny of Myxobolidae, and that the biological features of T. kitauei originated from the ancient Myxobolidae as exhibited by the non-specific infection site tropism and the ability to infect cyprinids.

Feeding habits of juvenile sea perch, Lateolabrax japonicus in tidal creek at Sangnae–ri Suncheon, Korea

During the study periods, total 143 individuals of Lateolabrax japonicus were collected. Body length (BL) range was 2.0-11.8 cm. Empty stomach occurred in 8.4%. The most abundant prey was copepods. Among copepods, Tigriopus japonicus was the most abundant prey appeared 32.1 in %F. Next important prey was shrimps and mysids. The results of analysis in ontogenetic changes, main prey of two small size classes (2.0-3.9 cm, 4.0-5.9 cm) were copepods. Thereafter, copepods percentage was decreased, but shrimps, mysids, fishes percentage was increased by increasing body length from 8.0 cm

Feeding Habits of Tridentiger bifasciatus in the Tidal Creek at Sangnae-ri, Suncheon, Korea

The feeding habits of Tridentiger bifasciatus were studied using 733 individuals collected in the tidal creek at Sangnae-ri, Suncheon, Korea, using a push net, monthly, from April 2011 to March 2012. The standard length (SL) of the specimens ranged from 1.5 to 8.2 cm. The stomach content analysis indicated that T. bifasciatus consumed mainly amphipods, such as Corophium sp., while copepods, polychaetes, and shrimps were other important prey species. In addition T. bifasciatus ate small quantities of crab larvae, fish, gastropod larvae, and insects. T. bifasciatus is a generalist that feeds on various zoobenthos, including fish. T. bifasciatus underwent an ontogenetic dietary shift. Smaller individuals (1-2 cm SL) fed mainly on amphipods. The proportion of amphipods decreased as body size increased, whereas the consumption of polychaetes increased gradually. The seasonal variation in the diet composition of T. bifasciatus was significant. Insects were common prey during summer, while the amounts of other prey, including polychaetes, were similar during spring, autumn, and winter.

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), but mean wet weight of preys per stomach (mW/ST) showed an opposite tendency (P > 0.05).

Seasonal Variation in the Species Composition of Fish Assemblages in the Coastal Waters off Gadeok-do, South Sea, Korea

Seasonal variations in species composition and abundance of the fish assemblages in the coastal waters off Gadeok-do were determined using monthly sample collection by a small otter trawl in 2010-2011. Of a total of 65 fishes collected, the dominant species were Leiognathus nuchalis, Clupea pallasii, Thryssa kammalensis, Engraulis japonicus, Repomucenus valenciennei, Sillago japonica, Trachurus japonicus, Pennahia argentatus, Okamejei kenojei, Cynoglossus joyneri, Pholis fangi, Pleuronectes yokohamae, and Zoarces gillii. These 13 fishes accounted for 92.8% of the total number of individuals collected. The number of fish species, number of individuals, biomass, and species diversity indices fluctuated with the seasons. The peak number of fishes occurred in April, whereas the biomass of fishes was highest in August. The numbers and biomass of fishes were lower in February corresponding with the low temperatures, and diversity indices were lower in January than in any other month.

Feeding Habits of Larval Japanese Anchovy Engraulis japonicus in Eastern Jinhae Bay, Korea

멸치(Engraulis japonicus)는 청어목(Clupeiformes), 멸치 과(Engraulidae)에 속하는 어류로 표층에서 군집 생활을 하고 (Kim et al., 2005), 주 산란기는 3월에서 6월이며 분리부성란 을 산란하는 특성을 가진다(Chyung, 1977). 멸치는 전 세계적 으로 식품으로 이용되는 어류 중 하나로 경제적 가치가 매우 높 은 상업성 어종이기 때문에 이들을 지속적으로 이용하기 위해 서는 초기생활사에 대한 연구가 필요할 것이다. 멸치를 대상으로 수행된 선행 연구를 살펴보면 요각류를 주 로 섭식한 광양만 후기 자어 멸치에 관한 연구(Park and Cha, 1995), 특정 환경에서의 변화하는 먹이이용성에 관한 연구 (Takahashi and Watanabe, 2005), 만각류 등의 섭식 비율이 높 은 멸치 성어에 관한 연구(Kim et al., 2013), 어란과 자치어의 분포 및 수송에 관한 연구(Kim and Pang, 2015), 초기성장과 발 달에 관한 연구(Lee and Go, 2003) 등이 알려져 있다. 향후 수 산자원관리를 위한 가입량 등에 대한 기초자료를 확보하기 위 해서는 멸치 자치어에 대한 생태학적 연구가 기본이 되어야 하 는데, 본 연구지역인 진해만 동부해역에 출현하는 멸치 자치어 의 식성 연구는 미비한 실정이다. 또한 진해만 동부해역은 거가 대교, 부산 신항만 건설 등과 같은 개발이 지속적으로 이루어지 고 있는 지역이며 향후 진해만 동부해역의 멸치 자치어 생태에 도 영향을 있을 것으로 생각된다. 본 연구의 목적은 멸치 자치어를 대상으로 주 먹이생물을 파 악하고, 성장에 따른 먹이생물 조성의 변화, 일주기 섭식율, 월 별 먹이생물 조성을 바탕으로 진해만 동부해역에 우점하여 분 포하는 멸치 자치어의 식성을 알아보고자 한다. 이는 이후 본 해 역에 출현하는 멸치 자치어 생태 변화를 파악하는데 도움이 되 고, 진해만 동부해역의 멸치 자원을 지속적으로 이용하기 위한 자료로 제공 될 것이다.

Feeding Habits of Javelin Goby Synechogobius hasta on Tide Flat in Sangnae-ri Suncheon, Korea

During the study period, a total of 158 individuals of Synechogobius hasta were collected. The range of body length (BL) was 15.4-44.5 cm. The stomachs of 26.6% of the individuals were empty. The most abundant prey was shrimp. Among shrimp, Exopalaemon orientis was the most abundant species, being present in 27% in %IRI (index of relative importance). Fishes and crabs were also abundant prey. Analysis of ontogenetic changes, suggested that shrimp were the main prey of S. hasta of two size classes (

Feeding habits of ocellate spot skate, Okamejei kenojei in the coastal waters of Gadoek-do, Korea

The feeding habits of Okamejei kenojei were studied using 242 specimens collected from October 2010 to September 2011 in the coastal waters of Gadeok-do, Korea. O. kenojei was carnivorous feeder that consumed mainly shrimps, crabs, and fishes. Its diet also included small quantities of stomatods, cephalopods, amphipods. The size of O. kenojei ranged from 10.4 to 47.4 cm in total length (TL). O. kenojei showed ontogenetic dietary shift.

Age and growth of the robust tonguefish Cynoglossus robustus in the Seto Inland Sea, Japan

This study provides data on the age and growth of the robust tonguefish, Cynoglossus robustus in the western part of the Hiuchi-Nada Sea in the Seto Inland Sea, Japan. Fish samples consisting of 299 robust tonguefish were collected monthly from June 2000 to May 2001. Maximum total length (TL) was larger for females than males. Growth was modeled using age estimates obtained from sagittal otoliths. The length–weight relationship followed an allometric growth pattern (b ≠ 3.0). Estimated ages ranged from 0.5 to 5.5 years for females and from 0.5 to 3.5 years for males. Von Bertalanffy growth equation parameters were derived from back-calculated TL fitted to TL at age; estimated values for females, were L∞=46.0 cm, k=0.278 year−1, and t0=−1.033 years, and values for males, were L∞=43.4 cm, k=0.281 year−1, and t0=−1.171. The growth performance index values for females and males were Φ=2.77 and Φ=2.72, respectively.

Feeding Habits of Hoplobrotula armata in the Coastal Waters of Geomun-do, Korea

The feeding habits of Hoplobrotula armata were studied using 269 specimens collected in the coastal waters of Geomun-do, Korea. The size of the specimens ranged from 5.6-56.8 cm in total length (TL). H. armata is a canivore that consumes mainly teleosts and decapods (shrimp, crabs and hermit crabs). Its diet also includes gammarid amphipods, cephalopods, polychaetes and copepods. Smaller individuals (