GENEEAL PLAN OF INQUIRIES TEOSECUTED. 5 



F. Eelationships. 



33. Do these fish go in schools after they have done spawning-, or 

 throughout tlie year, or are they scattered and solitary 'I 



34,. Have they any special friends or enemies f 



35. To what extent do they prey on other fish ; and on what species ? 



3G, To what extent do they suffer from the attacks of other fish, or 

 other animals? 



G. Food. 



37. What is the nature of their food ? 



38. Are there any special peculiarities in the manner of feeding of 

 these fish ? 



39. What amount of food do they consume ? 



H. Eeproduction. 



40. Is there any marked change in the shape or color of either sex 

 during the breeding-season, or any peculiar development of, or on, any 

 portion of the body, as the mouth, fins, scales, &c. °? 



* 41. Are there any special or unusual habits during the spawning- 

 season ? 



42. Is spawning interfered with by lines or nets, or otherwise ? 



43. At what age does the male begin to breed, and at what age the 

 female ! 



44. For how many years can these fish spawn ? 



45. Does the act of spawning exert an injurious effect ? 



46. Where do these fish spawn, and when ? 



47. Can you give any account of the process, whether males and 

 females go in pairs, or one female and two males ; whether the sexes are 

 mixed indiscriminately, &c. ? 



48. Is the water ever whitened or colored by the milt of the male '? 



49. What temperature of water is most? favorable for hatching ? 



50. At what depth of water are the eggs laid, if on or near the 

 bottom "? 



51. What is the size and color of the spawn "? 



52. What is the estimated number for each fish; and how ascer- 

 tained ? 



53. Answer the question for one season, and for the lifetime. 



54. Do the eggs, when spawned, sink to the bottom, and become 

 attached to stones, grass, &c. ; or do they fioat in the water until 

 hatched ? 



55. Do the fish heap up or construct any kind of nest, whether of 

 sand, gravel, grass, or otherwise; and if so, is the mouth, the snout, or 

 the tail used for the purpose, or what ; and if so, how is the material 

 transported ; or do they make any excavation in the sand or gravel ? 



50. Do they watch over their nest, if made either singly or in pairs ? 



57. When are the eggs hatched, and in what period of time after being- 

 laid 1 



58. What percentage of eggs laid is usually hatched ? 



59. What percentage of young attains to maturity ! 



60. What is the rate of growth "I 



61. Do the parents, either or both, watch over the young after they 

 are hatched ? 



62. Do they carry them in the mouth or otherwise ? 



63. What enemies interfere with or destroy the spawn or the young 

 fish ; do the parent fish devour them "? 



