Journal of the Faculty of Applied Biological Science, Hiroshima University Volume 18 Issue 1
1979-07-16 発行

ネズッポ属(Callionymus)魚類の食性について : I. ネズミゴチCallionymus punctatus LANGSDORFFの食性

On the Food Habits of the Dragonets, Genus Callionymus : I. Food Habits of Callionymus punctatus LANGSDORFF
Kakuda, Shunpei
Gushima, Kenji
Nakai, Kazuo
Ogushi, Yoshitaka
Murakami, Yutaka
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abstract
The dragonets, genus Callionymus, is very common and found frequently with other demersal fish in the catch of a small trawl in the Seto Inland Sea. In this study, the food habits of "Nezumigochi", Callionymus punctatus LANGSDORFF, have been investigated through analysis of their gut contents and benthos of their habitat, Sensui-shima in the central region of the Seto Inland Sea (Fig. 1). The material of 46 individuals were caught by a small trawl net. They ranged from 110 mm to 163 mm in standard length (Fig. 2). To compair the diet of this fish with the benthos of their habitat, 14 individuals in the sand area and 9 individuals in the Zostra zone were sampled by spear, the benthos of the area were also sampled by quardrat method (Fig. 4 ).

The general conclusions reached in this study are as follows:
1) The food organisms occurred in the guts were crustacea, bivalvia, gastropod a, and poly-chaeta. The crustacea contained the following organisms: branchiopoda, ostracoda, copepoda, mysidacea, cumacea, amphipoda, euphausiacea, macurura, anomura, brachyuran and stomatopoda. The main food organisms were cumacea for 72 % of the 46 stomachs, gastropoda for 65 %and ostracoda for 61 %. On the contrary, euphausiacea, macurura and anomura seemed to be preied on only occasionally, and branchiopoda, mysidacea and stomatopoda still more rarely (Table 1).
2) The difference between the diet of the male and female adult could not be statistically determined (Fig. 3). The diets of the specimens of 110-129mm and those of 130-164 mm were very similar.
3) The benthos of the sand area and that of the Zostera zone were clearly different in composition. Namely, in the benthos of the sand area Cypridina hilgendorfii (ostracoda) occupied 53%, but in the benthos of the Zostera zone Musculus (Musculista) senhousia (bivalvia) 87%. The composition of the food organisms and benthos sampled in each habitat were very similar to each other (Table 3). In the sand area, Cypridina hilgendorfii occupied 53% of the benthos but 79% in the food organisms. In the Zostera zone, Musculus (Musculista) senhousia occupied 87% of the benthos, but 59% in the food organisms (Table 2).
4) Musculus (Musculista) senhousia, the main food organisms of C. punctatus in the Zostera zone, were rarely taken in by the common inhabitant of the Zostera zone around Sensui-shima: Pseudoblennius cottoides, Agrammus agrammus and Hexagrammos otakii. But gammaridae that occupied only 6% in the food organisms of C. punctatus in the Zostera zone were often eaten by these 3 species mentioned above (Fig. 5). Accordingly, it is considered that C. punctatus is not in competition with these 3 species for prey.