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Notes on the Reproduction of Teleostean Fishes 

 in the South-Western District. 



By 

 Ernest W. L. Holt and L. W. Byrne. 



Morone labrax. Linn. Bass. 



Towards the end of May a large female bass in one of the Aquarium 

 tanks appeared to be approaching ripeness, and constantly swam round 

 the tank followed by one or more of its companions, probably of the 

 opposite sex. A fine-meshed net was accordingly placed over the over- 

 flow from the tank in question, and on the morning of the 29th May 

 was found to contain a very large number of eggs, undoubtedly 

 attributable to this species, the only other Teleostean inmates being 

 turbot, congers, pollack, rocklings, and two species of wrasse. 



All the eggs proved to be unfertilised, or, at most, showed only an 

 approach to segmentation, which may have been due to the spermatozoa 

 of a rockling. Circumstances seemed strongly to point to the fact 

 that the eggs are not all shed at once, but owing to an unfortunate 

 series of accidents with the net it is impossible to speak on this point 

 with absolute certainty. 



Although the bass is a common British fish, its ova find no place in 

 the records of British naturalists, and are only known from the de- 

 scriptions of Kaffaele,* who obtained them both from parents living 

 in the tanks of the Naples Laboratory and from the neighbouring sea. 



The eggs observed by us at Plymouth are spherical, and, while living 

 but unfertilised, measure from 125 to I'o-i mm. in diameter. Eaftaele 

 gives 1-155 to 12 mm. as the diameter of Naples examples. The latter 

 have an oil-globule of -332 to -366 mm. The Plymouth eggs have 

 often two or more oil-globules, which soon coalesce to form a single 

 globule of -39 or 40 mm., pale yellowish to the naked eye, but perfectly 

 colourless by transmitted light under the microscope. 



* Mittheil. Zool. Stat. Neap., viii., 1888. 



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