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アサヒアナハゼの産卵


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Title: アサヒアナハゼの産卵
Other Titles: The Spawning of the Sea Sculpine, Pseudoblennius cottoides
Authors: 塩垣, 優 / 道津, 喜衛
Authors (alternative): Shiogaki, Masaru / Dotsu, Yoshie
Issue Date: Dec-1974
Publisher: 長崎大学水産学部
Citation: 長崎大学水産学部研究報告, v.38, pp.71-76; 1974
Abstract: Three mature females of the cottid fish, Pseudoblennius cottoides (Richardson), being from 102 to 131 mm. in total length, were collected from shallow water at Nomo Harbor near Nagasaki City on January 11, 1971 and reared for about one month in a rectangular glass aquarium (65 cm.×35 cm.×29 cm.) provided with a recirculatory system. During the rearing period, 2 spawnings ocurred while the male fish was not present in the aquarium. The first spawning was observed on January 22, 11 days after the commencement of the rearing. About 120 eggs sticked one another and formed a globular sponge-like mass, being about 1 cm. in diameter, which was laid at a corner of the aquarium without attaching to the sandbottom (Fig. 1). The eggs had been fertilized but were still before the first cleavage stage. A female adult stayed close to the egg mass, but no parental care was observed. The second spawning comprising of 3 egg masses was found 3 days after the first spawning. The largest one of the egg masses was an irregular at form measuring 5 cm. by 4 cm. and possesed about 570 eggs. Two other egg masses were similar in form, both globular measuring about 2 cm. in diameter. The eggs were thoroughly fertilized and were in the early embryonic developmental stage such as 2-cell or 4-cell stage. The fertilized egg masses were laid in the aquariun where the 3 females had been kept separately from the male. This shows, therefore, that the eggs were internally fertilized and subsquently spawned out. Eggs were stripped from one of the 3 females, being 129 mm. in total length, through the protrusile oviduct into the sea water with absolutely no contact to the milt from the male. Yet, the eggs were fertilized. It proves again that the eggs are fertilized internally by the spermatozoa which might be implanted beforehand in the female by copulation. The eggs are spherical in form, me from 1.85 to 1.91 mm. in diameter and provided with a narrow pervitelline space and a light greenish yellow yolk (Fig. 2). The incubation took 17 to 20 days until hatching at the temperature of about 12℃. The newly hatched out larvae being from 6.55 to 7.20 mm. long swam around in an aquarium. The comsumption of the was completed within 5 days after hatching and the size of the larvae attained to over 8 mm.
URI: http://hdl.handle.net/10069/30800
ISSN: 05471427
Type: Departmental Bulletin Paper
Text Version: publisher
Appears in Collections:第38号

Citable URI : http://hdl.handle.net/10069/30800

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