﻿168 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  narrow 
  near 
  the 
  middle, 
  so 
  that 
  the 
  general 
  shape 
  will 
  be 
  like 
  a 
  dumb- 
  

   bell 
  with 
  a 
  very 
  short 
  handle. 
  Across 
  the 
  narrow 
  part 
  is 
  to 
  be 
  stretched 
  

   a 
  screen 
  of 
  ^-inch 
  wire 
  cloth, 
  which 
  will 
  confine 
  the 
  spawners 
  to 
  the 
  

   deeper 
  end 
  of 
  the 
  pond, 
  while 
  the 
  fry, 
  following 
  their 
  instinct 
  of 
  

   moving 
  upstream, 
  will 
  find 
  their 
  way 
  through 
  the 
  screen 
  into 
  the 
  

   upper, 
  shallower 
  end. 
  This 
  method 
  would 
  apparently 
  not 
  only 
  save 
  

   much 
  labor 
  in 
  transferring 
  the 
  fry, 
  but 
  obviate 
  the 
  risk 
  involved 
  in 
  

   handling 
  thetn. 
  

  

  If 
  it 
  is 
  desired 
  to 
  hold 
  the 
  bass 
  until 
  they 
  attain 
  their 
  full 
  growth, 
  

   the 
  fry 
  are 
  transferred 
  to 
  troughs 
  or 
  pools 
  where 
  they 
  are 
  reared 
  in 
  a 
  

   purely 
  artificial 
  manner 
  — 
  that 
  is, 
  tamed 
  and 
  trained 
  to 
  take 
  prepared 
  

   food. 
  For 
  this 
  purpose 
  modifications 
  in 
  the 
  shape 
  and 
  arrangement 
  of 
  

   the 
  spawning-pond 
  are 
  necessary, 
  somewhat 
  as 
  described 
  above 
  for 
  the 
  

   combination 
  pond. 
  The 
  shallow 
  part 
  near 
  the 
  inlet 
  has 
  a 
  long, 
  narrow 
  

   neck 
  and 
  the 
  general 
  shape, 
  where 
  the 
  ground 
  permits, 
  follows 
  the 
  

   outline 
  of 
  a 
  gourd. 
  That 
  part 
  which 
  resembles 
  the 
  handle 
  is 
  screened 
  

   ofl' 
  from 
  the 
  remainder 
  with 
  wire 
  netting, 
  with 
  a 
  quarter-inch 
  or 
  less 
  

   mesh. 
  The 
  young 
  fry, 
  after 
  the 
  dispersal 
  of 
  the 
  school, 
  seek 
  the 
  shal- 
  

   low 
  waters, 
  which, 
  warmed 
  by 
  the 
  sun, 
  at 
  this 
  time 
  of 
  year 
  afford 
  rich 
  

   pasture 
  of 
  Cyclojjs, 
  Baphnia, 
  young 
  Gorixa, 
  and 
  other 
  small 
  invertebrates. 
  

   Following 
  the 
  natural 
  inclination 
  of 
  young 
  fishes 
  to 
  head 
  toward 
  the 
  

   source 
  of 
  the 
  water 
  supply, 
  they 
  pass 
  through 
  the 
  screen 
  and 
  collect 
  

   within 
  the 
  neck 
  of 
  the 
  i)ond, 
  where 
  the 
  food 
  supply 
  will 
  be 
  found 
  to 
  be 
  

   greater 
  than 
  around 
  the 
  margin. 
  From 
  this 
  part 
  of 
  the 
  pond 
  the 
  fry 
  

   have 
  no 
  inclination 
  to 
  retreat, 
  and 
  the 
  parent 
  fish 
  can 
  not 
  follow 
  and 
  

   devour 
  them. 
  

  

  TROUGHS. 
  

  

  The 
  ordinary 
  horizontal 
  trough 
  in 
  general 
  use 
  in 
  trout-culture 
  is 
  well 
  

   adapted 
  to 
  raising 
  young 
  bass 
  fry. 
  A 
  trough 
  12 
  to 
  14 
  feet 
  long 
  with 
  4 
  

   inches 
  depth 
  of 
  water 
  at 
  57°, 
  changing 
  2 
  gallons 
  per 
  minute, 
  will 
  sup- 
  

   port 
  from 
  3,000 
  to 
  5,000 
  black-bass 
  fry, 
  and 
  twice 
  or 
  three 
  times 
  as 
  many 
  

   rock 
  bass 
  will 
  live 
  comfortably 
  under 
  like 
  conditions. 
  For 
  bass 
  of 
  

   larger 
  size, 
  fiugerliugs 
  and 
  upward, 
  vats 
  or 
  i)Ools 
  answer 
  better 
  than 
  

   troughs. 
  The 
  troughs 
  can 
  be 
  so 
  arranged 
  that 
  the 
  water 
  discharged 
  

   from 
  them 
  furnishes 
  the 
  sui>ply 
  for 
  one 
  or 
  more 
  pools. 
  The 
  shape, 
  size, 
  

   and 
  number 
  of 
  the 
  pools 
  must 
  be 
  regulated 
  by 
  the 
  topography 
  of 
  the 
  

   land, 
  though 
  they 
  should 
  not 
  be 
  wider 
  than 
  G 
  foet, 
  nor 
  with 
  a 
  dejjth 
  of 
  

   water 
  greater 
  than 
  2 
  feet, 
  and 
  either 
  lined 
  with 
  plank 
  or 
  built 
  of 
  brick 
  

   or 
  stone. 
  Wire 
  netting 
  or 
  guard-bbards, 
  projecting 
  I 
  to 
  li 
  feet 
  above 
  

   the 
  ground, 
  prevent 
  the 
  entrance 
  of 
  snakes 
  and 
  other 
  enemies. 
  As 
  

   with 
  all 
  ponds, 
  provision 
  is 
  made 
  to 
  entirely 
  empty 
  one 
  pool 
  without 
  

   interfering 
  with 
  the 
  water 
  supply 
  of 
  another, 
  and 
  to 
  have 
  a 
  good 
  fall 
  

   from 
  inlet 
  to 
  outlet. 
  The 
  length 
  of 
  the 
  pool 
  must 
  be 
  regulated 
  by 
  the 
  

   lay 
  of 
  the 
  land, 
  and, 
  if 
  long, 
  it 
  is 
  advantageous 
  to 
  divide 
  the 
  pool 
  into 
  

   sections, 
  with 
  movable 
  screens 
  of 
  wire 
  cloth 
  for 
  convenience 
  in 
  handling 
  

   several 
  sizes 
  of 
  fish. 
  

  

  