염분에 대한 두줄망둑의 내성범위를 파악하기 위한 일환으로 이들의 생존, 성장 및 산소소비에 미치는 염분의 영향을 40일간 사육실험을 통하여 검토하였다. 두줄망둑의 생존율은 염분 10.1‰ 이상에서 90%이상을 나타냈으나, 염분 3.4‰ 이하에서는 유의한 감소를 나타냈고, 담수에서는 40일째 32.5%의 생존율을 보였다. 체장과 체중의 증가 및 성장률은 13.4∼33.6%o의 염분 범위에서 유사

This study describes the developmental process of gonads in chameleon goby, Tridentiger trigonocephalus from the stage of hatching to 100 days after hatching (DAH). Based on histological observation, the primordial germ cells were observed in mesentery between mesonephric duct and gut at 15 DAH (total length, TL: 6.8±0.2 mm). At 20 DAH (TL: 7.9±0.1 mm), the primordial gonad began to protrude into peritoneal cavity and developed between mesonephric duct and gut. Initial ovarian differentiation was identified by the presence of ovarian cavity and oogonia in the gonads at 55 DAH (TL: 21.1±1.3 mm). Testicular differentiation started at 65 DAH (TL: 23.7±0.9 mm) with appearance of spermatogonial cells in the gonads. These findings indicate that sex differentiation in T. trigonocephalus occurs earlier in females than males, suggesting that this species can be classified as an undifferentiated gonochorist.

The objective of this study was to characterize the reproductive cycle of the chameleon goby, T. trigonocephalus. Gonadal development was investigated using a histological method. Specimens were collected monthly, from April 2009 to March 2010. The gonadosomatic index (GSI) of females began to increase in April, reaching the maximum in May, and declined sharply in August. In males, the GSI began to increase in April and reaching the maximum in July. The annual reproductive cycle of T. trigonocephalus can be divided into four successive stages in females: the growing (November- March), maturing (April-May), ripe and spawning (June-July), and recovery (August-October) stages. Males passed through growing (November-March), maturing (April-June), ripe and spermiation (July-August), and recovery (September-October) stages. These results indicate the spawning season is from June to July. The relationship between fecundity (Fc) and body length (BL) was Fc=86.1511BL2.6506. Fecundity was ranged from 3,448-9,654 eggs in a BL of 4.8-7.2 cm and it was increased as BL increased.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants derived from incomplete combustion of carbons and crude oil. In this study, we investigated the effects of benzo[a]pyrene (B[a]P), a representative PAHs on in vitro sex steroid hormone production and germinal vesicle breakdown (GVBD) using isolated oocytes of longchin goby (Chasmichthys dolichognathus) and chameleon goby (Tridentiger trigonocephalus). Oocytes in diameters of 0.8-0.9 (end vitellogenic stage) and 0.9-1.0 mm (germinal vesicle migratory stage) from longchin goby and 0.5 mm (fully vitellogenic stage) from chameleon goby were used. In GVBD assay, B[a]P at 10 nM stimulated GVBD in the oocytes of 0.8-0.9 mm from longchin goby. B[a]P at 1 nM stimulated GVBD in the oocytes with diameter 0.5 mm from chameleon goby. In steroid production from oocytes of longchin goby, B[a]P at 100 nM decreased testosterone (T) production, B[a]P at 1,000 nM increased estraiol-17 (J (E2) production and 10 and 100 nM increased -dihydroxy-4-pregnen-3-one () production in the oocytes with diameter 0.8-0.9 mm. B[a]P at 1,000 nM increased E2 production, 100 and 1,000 nM increased production in the oocytes with diameter 0.9-1.0 mm. In steroid production of oocytes from chameleon goby, B[a]P at 1,000 nM increased production. B[a]P at 10 nM increased production. In the ratio of to T (/T), B[a]P at 100 and 1,000 nM increased /T in the oocytes of longchin goby. B[a]P at 100 nM also increased /T in the oocytes of chameleon goby. Taken together, these results suggest that B[a]P have not only weak estrogenic effects but progestogenic effects on oocyte maturation.

본 연구는 해산어류인 두줄망둑의 난모세포 성숙과정에서 생성․분비되는 성 스테로이드 호르몬의 종류와 그 외 다른 특이 호르몬의 존재 여부를 밝히고자 성숙기 난모세포 크기별 즉 평균난경 0.45, 0.48 그리고 0.50 mm인 난모세포들을 대상으로 방사표지된 스테로이드 전구물질, [3H]-pregenenolone을 첨가하여 24시간 배양하였다. 배양 후 배양액과 난모세포로부터 스테로이드 호르몬을 추출하여 thin later chromatography (TLC)를 거쳐 1차 분리된 대사물질은 high performance liquid chromatography (HPLC)와 gas chromatography-mass spectrometry (GC/MS)로 동정하였다. TLC 분석 결과, 성숙기 난모세포의 주요 스테로이드 대사물질로는 난경 0.45 mm인 난모세포에서는 estraiol-17β (E2)와 17 α-hydroxyprogesterone (17αP), 난경 0.48 mm인 난모세포에서는 17α,20α-dihydroxy-4-pregnen-3-one (17α20αP), 17α,20β-dihydroxy-4-pregnen-3-one (17α20βP) 그리고 17α,20β21-dihydroxy-4-pregnen-3-one (17α20β21P), 난경 0.50 mm인 난모세포에서는 estrone (E1), E2 그리고 17αP의 표준물질과 일치하였다. 위의 세 난경의 난모세포로부터 생성된 주요 대사물질에 해당하는 fraction들은 각각 HPLC를 거쳐 GC/MS로 재확인하였으나, E1만이 동정되었다. 성숙기 두줄망둑의 난모세포에서는 T의 생성은 거의 관찰되지 않았고, E1과 E2를 비롯한 progestins 계의 steroid 만이 관찰되었다. 특히 3종류의 progestin 중에서 17α20β21P의 대사량이 가장 높았으며, 17α20βP의 대사량이 가장 낮게 나타났다. 또한, E1의 대사량이 E2의 대사량보다 더 높은 것으로 나타났다. 본 연구결과, 두줄망둑의 성숙 난모세포에서 생성되는 progestin은 기존에 어류에서 보고된 3종류의 호르몬이 모두 대사되는 것으로 생각되어진다. 또한 난경 0.48 mm인 난모세포에서 progestin의 대사량이 가장 높았으며, 난경 0.50 mm인 난모세포에서는 이들 progestin의 대사량 감소와 함께 E1과 E2의 대사량이 증가하는 특징을 나타냈다. 이와 관련하여 앞으로 성숙단계로 이행하는 과정에서의 E1과 E2의 역할 규명과 함께 progestin 대사물질 종류별 대사율 분석이 수반되어야 할 것이다.