194 THE SUCKER FAMILY. 



Sarsia. The young forms reach 21 mm. in July, and the body 

 is now richly pigmented. Spots of a darker hue occur at 

 intervals on the head, dorsal and anal fins, tail and sides. The 

 first part of the dorsal fin, viz. that which was differentiated at 

 11 mm., is now more or less fleshy, forming an obscure ridge. 

 All traces of the larval tail have disappeared. Those of 90 mm. 

 during this month are probably of the third year. 



Small specimens of 6 mm. are occasionally obtained off-shore 

 in August, while the older forms of the season range from 27 to 

 37 mm., and they practically agree with the adults in external 

 characters. Those of 55 to 80 mm. represent the growth during 

 the second, and perhaps, the latter, even the third year. 



In September small post-larval forms of about 4 mm. are 

 still procured in the bottom-net, and older forms of 9'5 mm. 

 in the mid-water net, the larval tail in the latter having dis- 

 appeared. Thus the degree of development is not necessarily 

 indicated by size, as for instance was shown in an example of 

 11 mm. captured on the 22nd September in the bottom-net. 

 Though of precisely the same length as that described on the 

 16th May, the posterior end had no trace of the larval tail as in 

 the latter month. The notch separating the upper region of the 

 tail had disappeared with the larval organ, and the true fin-rays 

 of the tail were symmetrically arranged. 



In the first half of October, larval forms rather less than 

 4 mm. in spirit have been met with, so that, if the diagnosis 

 be correct, the spawning-period is sufficiently prolonged. This 

 is the more probable as unmistakable forms of 8 mm. have been 

 procured at the same time. 



One of 45 mm. on the 10th of November probably gives the 

 limit of growth for the season. An interesting table of measure- 

 ments and calculated ages of various examples is given by 

 Mr J. R. Tosh \ The young suckers are eaten by many young 

 food-fishes, the larger being frequently found in the stomach 

 of the cod and other fishes. 



1 12th Ann. S.F.B. Report, p. 335, 1894. 



