298 BULLETIN OP THE BUREAU OP FISHERIES. 



A later notice of the annual spawning of the European lobster after transplanta- 

 tion to artificial ponds in New Zealand has been given by Anderton (5), whose observa- 

 tions on the molting and breeding habits of this animal under a complete change of 

 environment are most interesting and are referred to in various parts of this work 

 (seep. 302). At the time of writing, when his observations had extended over 3 years, 

 several of the lobsters had laid two batches of eggs, and one, which bore attached eggs 

 at the time of shipment, was known to have spawned three times in 3 years and 7 

 months. The record for the latter lobster is as follows : 



Arrived with a few eggs still attached, January, 1906. 



First molt, in absence of male, January, 1907. 



Second molt, followed by copulation, November 21, 1907. 



First spawning under new conditions, January 24, 1908. 



Hatching of first batch of eggs, November 23 to December 28, igo8. 



Second spawning; date not determined, but before March 12, 1909. 



These animals were confined in small ponds with concreted bottom, and regulated 

 tidal flow, and were regularly fed and skillfully cared for. It is interesting to notice 

 that while the seasons are reversed in the southern hemisphere, the local range of 

 temperature in New Zealand is similar to that at bottom of Vineyard Sound, Massa- 

 chusetts, the lowest average temperature of 3° C. (37|° F.) being recorded for July 

 (compare p. 182), and the highest average of 13° C. (55!° F.) from December to 

 February. 



An interval of 65 days ensued between copulation and spawning, and the fosterage 

 period from egg laying to the hatching of the first young was 10 months to within a 

 day. While it can not be maintained that these novel conditions give the usual Spawning 

 habits for Homarus gammarus until similar results are obtained within its natural range 

 (compare Appell6f 's experiments, given above) , they show that the lobster is remark- 

 ably plastic and able to withstand considerable change when directed by skillful hands. 



NUMBER OF EGGS PRODUCED. 



The freshly laid eggs are of a dark green, almost black hue, when seen in mass, 

 and somewhat irregular in shape, but they soon plump out and become nearly spherical 

 or ovoidal in form. As the eggs develop they increase in size, become elongated, and, 

 owing to the gradual assimilation of the dark yolk, lighter in color. (Compare fig. 33, a &.) 

 This is most noticeable toward the close of the period of development, when the phrase 

 "old" or "light" egg lobster is commonly used by fishermen to distinguish them from 

 the "black" egg lobsters, which have more recently spawned. 



The fresh egg measures approximately ^t i^^ch in diameter (1.5 to 1.7 mm.) and 

 weighs ffUTTTr ounce or ^1^ gram. A fluid ounce of eggs weighs about i ounce avoir- 

 dupois. The number of eggs laid is proportionate to the volume of the ovary and of 

 the body, and varies from about 3,000 to nearly 100,000 in animals from 8 to 19 inches 

 long. 



