Embryology and Growth of Fishes 149 



kan blackfish (Dallia) has been fed frozen to dogs, escaping alive 

 from their stomachs after being thawed out. Many of the cat- 

 fishes (Silurida) will live after lying half -dried in the dust for 

 hours. The Dipnoan, Lepidosiren, lives in a ball of half-dried 



FIG. 114. Ice-fish, Salanx hyalocranitis Abbott. Family Salangidce. Tient- 

 sin, China. 



mud during the arid season, and certain fishes, mostly Asiatic, 

 belonging to the group Labyrinthici, with accessory breathing 

 organ can long maintain themselves out of water. Among these 

 is the China-fish (Ophiocephalus), often kept alive in the Chinese 

 settlements in California and Hawaii. Some fishes can readily 



FIG. 115. Alaska Blackfish, Dallia pectoralis (Bean). St. Michaels, Alaska. 



endure prolonged hunger, while others succumb as readily as a 

 bird or a mammal. 



The Effects of Temperature on Fish. The limits of distribu- 

 tion of many fishes are marked by changes in temperature. Few 

 marine fishes can endure any sudden or great change in this 

 regard, although fresh-water fishes adapt themselves to the 

 seasons. I have seen the cutlass-fish (Trichiurus) benumbed 

 with cold off the coast of Florida while the temperature was 

 still above the frost-line. Those fishes which are tenacious of 

 life and little sensitive to changes in climate and food are most 

 successfully acclimatized or domesticated. The Chinese carp 



