Early life history of a catadromous sculpin in western Japan
Early life history of a catadromous sculpin in western Japan
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日本西部降水杜父父鱼的早期生活史
DOI：
10.1023/a:1007439307867
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发表时间：
1999
影响因子：
1.4
通讯作者：
S. Harada
中科院分区：
文献类型：
--
作者：
I. Kinoshita;K. Azuma;S. Fujita;I. Takahashi;K. Niimi;S. Harada
为了阐明卡氏杜父鱼（Cottus kazika，Cottidae）的早期生活史，根据从日本西部海岸和河口采集的仔稚鱼，研究了其个体发育、骨骼学、分布、迁移和食性。鳍的发育顺序为胸鳍（P1）-背软鳍部（D2）-肛鳍（A）-背棘部（D1）-腹鳍（P2）。而钙化的形态为P1-P2-D1-D2-A。C. kazika与日本沿海杜父鱼的区别在于大的前鳃盖棘，明显的顶骨棘，大而密集的着色胸鳍和相对较深的身体。C. kazika和Myoxocephalus polyacanthocephalus + Enophrys野牛具有这4个个体发育特征。根据矢状面上的生长轮数与全长的关系，孵化时胚胎的大小估计为5.2 mm。孵化后10天的仔鱼估计为7 mm，20天为9 mm，30天为11 mm。1987年在四万十河口收集的幼虫孵化日期在1月新月前后达到高峰。在Yura河口外的岩石海岸，在高盐度（> 33 ppt）下，使用aqualamp收集了许多4.3至5.9 mm的游离胚胎，但在河口没有收集到。从海滩样本中，身体大小的季节性变化每年都有所不同，并没有一致的增长模式被发现，虽然青少年一般在3月下旬和4月比1月和2月更大。很少有幼虫收集沿着海岸线，那里没有相邻的河流。仔稚鱼的食性随生长而变化。多毛类幼虫，枝角类和桡足类被发现在小于6毫米的前屈幼虫。钩虾是超过6毫米的幼虫的重要食物项目之一。超过12毫米的幼虫几乎完全以钩虾为食。在Shimanto河口，1月和2月，幼体和幼体停留在河口附近的滞流层中，温度和盐度分别保持在12 °C和20 ppt左右。幼鱼倾向于在3月移动时，停滞层消失在河口。
To clarify the early life history of Cottus kazika (Cottidae), the ontogeny, osteology, distribution, migration and food habit were examined based on larvae and juveniles collected from coasts and estuaries in western Japan. The sequence of fin completion was pectoral (P1)-dorsal soft-ray part (D2)-anal (A)-dorsal spine part (D1)-pelvic (P2). However, that of calcification was P1-P2-D1-D2-A. Larvae and juveniles of C. kazika are distinguished from those of coastal sculpins of Japan by large preopercle spines, conspicuous parietal spines, the large and densely pigmented pectoral fin and the relatively deep body. C. kazika and Myoxocephalus polyacanthocephalus plus Enophrys bison share these four ontogenetic characters. From the relationship between the growth ring count on the sagittae and total length, the size of embryos at hatching is estimated at 5.2 mm. Larvae are estimated to reach 7 mm in 10 days, 9 mm in 20 days and 11 mm in 30 days after hatching. Hatching dates for larvae collected in the Shimanto estuary in 1987 peaked during the period around the new moon in January. Many free embryos ranging from 4.3 to 5.9 mm were collected using an aqualamp at a rocky shore outside the Yura River mouth, at high salinity (> 33 ppt), but none were collected in the estuary. From beach samples, seasonal changes in body size varied from year to year, and no consistent growth pattern was found, although juveniles were generally larger in late March and April than in January and February. Very few larvae were collected along shorelines where there were no adjacent rivers. Food habit of larvae and juveniles changed with growth. Polychaete larvae, cladocerans and copepods were found in preflexion larvae less than 6 mm. Gammarids were one of the important food items for larvae over 6 mm. Juveniles over 12 mm almost exclusively fed on gammarids. In the Shimanto estuary, larvae and juveniles stayed near the river mouth in January and February, within a stagnant layer where temperature and salinity remained about 12 °C and 20 ppt, respectively. Juveniles tended to move in March when the stagnant layer disappeared in the estuary.