ROPES ET AL.: SIZE. AGE. AND SEX OF OCEAN QUAHOGS OFF LONG ISLAND, NY. 



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FIGURE 10. — i a i Differentiated gonadal tissue section in the mature condition from an 18-yr-old male ocean quahog, Arctica islandica , 

 57.8 mm shell length, (b) Enlargement of spermiogenesis in a portion of a gonadal tubule, (c) Differentiated gonadal tissue section in 

 the mature condition from a 16-yr-old female quahog, 59.8 mm shell length, (d) Enlargement of ripe oocytes in a tubule. 



Gonadal Condition vs. 

 Size and Age 



In an analysis of gonadal condition relative to 

 age and size, quahogs in the undifferentiated, 

 immature condition ranged from 2 to 8 yr old, 

 averaged 5.0 yr old, and were from 19 to 46 mm 

 long and averaged 34.4 mm (Table 1). This condi- 

 tion was found in 27% of the gonads in the sample. 



For the three types of differentiated gonads, 

 quahogs with sparse tubule development com- 

 prised 15% of the sample. Males ranged from 3 to 7 

 yr old, averaged 4.6 yr old, and were from 21 to 44 

 mm long and averaged 33.8 mm; females ranged 

 from 5 to 7 yr old, averaged 6.0 yr, and were from 

 36 to 42 mm long and averaged 38.4 mm. This 

 category contained the smallest and youngest 

 female in the sample: 38 mm long and 5 yr old. 



Quahogs with moderate tubule development 



comprised 37% of the sample. Males ranged from 3 

 to 10 yr old, averaged 6.1 yr, and were from 20 to 48 

 mm long and averaged 37.2 mm; females ranged 

 from 7 to 8 yr old, averaged 7.1 yr, and were from 39 

 to 45 mm long and averaged 41.8 mm. This cate- 

 gory contained the smallest and youngest male in 

 the sample, which was 20 mm long and 3 yr old 

 (Fig. la, b). 



Sexually mature quahogs comprised 21% of the 

 sample. Males ranged from 5 to 18 yr old, averaged 

 9.8 yr, and were from 36 to 58 mm long and aver- 

 aged 47.1 mm; females ranged from 6 to 16 yr old, 

 averaged 13.2 yr, and were from 41 to 60 mm long 

 and averaged 55.0 mm. The smallest mature 

 quahog found was a male 36 mm long and 6 yr old, 

 although a 5-yr-old, 41 mm long male was also 

 mature; the smallest and youngest mature female 

 found was 41 mm long and 6 yr old. 



None of the gonads contained germinal cells 



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