﻿MANUAL 
  OF 
  FISH-CULTURE. 
  95 
  

  

  THE 
  FIELD 
  STATION. 
  

  

  For 
  the 
  egg-collecting 
  station 
  a 
  point 
  was 
  selected 
  on 
  a 
  tributary 
  of 
  

   the 
  Au 
  Sable, 
  iiowing 
  about 
  1,000 
  gallons 
  per 
  minute, 
  near 
  where 
  it 
  

   empties 
  into 
  the 
  river. 
  A 
  dam 
  was 
  thrown 
  across 
  the 
  stream 
  and 
  100 
  

   feet 
  above 
  a 
  screen 
  was 
  built 
  to 
  prevent 
  the 
  fish 
  from 
  escaping 
  in 
  that 
  

   direction. 
  The 
  dam 
  is 
  simply 
  constructed 
  by 
  banking 
  up 
  mud, 
  sand, 
  

   and 
  turf, 
  and 
  has 
  a 
  frame 
  sluiceway 
  3 
  feet 
  long, 
  2 
  feet 
  wide, 
  and 
  2 
  feet 
  

   deep. 
  In 
  the 
  sluiceway 
  is 
  inserted 
  a 
  double 
  screen 
  of 
  :|-inch 
  mesh 
  wire 
  

   netting, 
  two 
  screens 
  being 
  necessary 
  to 
  keep 
  the 
  overflow 
  clear 
  and 
  

   reduce 
  as 
  low 
  as 
  possible 
  any 
  loss 
  of 
  fish 
  through 
  this 
  outlet. 
  The 
  

   inclosure 
  accommodates 
  about 
  10,000 
  fish. 
  For 
  holding 
  the 
  eggs 
  two 
  

   pairs 
  of 
  troughs 
  are 
  placed 
  on 
  standards 
  driven 
  into 
  the 
  bed 
  of 
  the 
  

   stream, 
  with 
  a 
  passage 
  between 
  them 
  wide 
  enough 
  to 
  admit 
  a 
  man. 
  

   Fish 
  are 
  obtained 
  with 
  rod 
  and 
  line, 
  until 
  they 
  begin 
  to 
  run 
  from 
  the 
  

   dee]} 
  pools 
  upon 
  the 
  spawning-grounds, 
  when 
  much 
  better 
  results 
  are 
  

   obtained 
  with 
  nets. 
  With 
  an 
  ordinary 
  seine 
  at 
  the 
  approach 
  of 
  the 
  

   spawning 
  season, 
  the 
  fish 
  can 
  be 
  taken 
  in 
  large 
  numbers 
  from 
  their 
  

   spawning-beds. 
  As 
  the 
  season 
  advances 
  and 
  too 
  many 
  fish 
  are 
  caught 
  

   that 
  have 
  already 
  spawned, 
  operations 
  are 
  suspended. 
  

  

  The 
  water 
  is 
  received 
  through 
  two 
  1-inch 
  orifices 
  in 
  a 
  bulkhead 
  about 
  

   9 
  feet 
  long, 
  situated 
  at 
  the 
  head 
  of 
  these 
  troughs 
  and 
  fed 
  by 
  a 
  roughly- 
  

   constructed 
  raceway 
  leading 
  from 
  a 
  small 
  sj)ring 
  about 
  6 
  rods 
  distant 
  

   on 
  the 
  hillside. 
  The 
  water 
  from 
  each 
  of 
  the 
  openings 
  feeds 
  two 
  

   troughs, 
  so 
  placed 
  that 
  the 
  lower 
  end 
  of 
  the 
  upper 
  one 
  rests 
  upon 
  the 
  

   head 
  of 
  the 
  other, 
  thus 
  creating 
  a 
  fall 
  of 
  nearly 
  the 
  height 
  of 
  the 
  

   troughs. 
  Each 
  trough 
  is 
  11 
  feet 
  Igng, 
  5 
  inches 
  deep, 
  and 
  consists 
  of 
  a 
  

   double 
  row 
  of 
  boxes, 
  each 
  box 
  17 
  inches 
  long, 
  15 
  inches 
  broad, 
  and 
  2 
  

   inches 
  deep, 
  giving 
  a 
  capacity 
  of 
  from 
  8,000 
  to 
  10,000 
  eggs. 
  

  

  As 
  soon 
  as 
  ripe 
  fish 
  are 
  found 
  among 
  those 
  caught 
  on 
  the 
  spawning- 
  

   beds, 
  the 
  pond 
  is 
  hauled 
  with 
  a 
  seine 
  and 
  the 
  fish 
  are 
  looked 
  over 
  twice 
  

   a 
  week 
  until 
  all 
  the 
  eggs 
  are 
  taken. 
  When 
  the 
  season 
  is 
  fairly 
  opened 
  

   the 
  spawn 
  may 
  be 
  taken 
  from 
  most 
  of 
  the 
  fish 
  immediately 
  after 
  they 
  

   are 
  caught, 
  thus 
  obviating 
  the 
  difficulty 
  of 
  transferring 
  them 
  from 
  the 
  

   point 
  of 
  capture 
  to 
  the 
  pond, 
  in 
  some 
  cases 
  a 
  distance 
  of 
  3 
  or 
  4 
  miles. 
  

  

  TAKING 
  THE 
  .SPAWN 
  — 
  DRY 
  PROCESS. 
  

  

  A 
  good 
  spawn-taker 
  can 
  tell 
  at 
  a 
  glance 
  if 
  a 
  female 
  is 
  ripe, 
  and 
  only 
  

   in 
  such 
  condition 
  should 
  an 
  attempt 
  be 
  made 
  to 
  take 
  her 
  eggs. 
  After 
  

   the 
  ripe 
  males 
  and 
  females 
  are 
  placed 
  in 
  separate 
  tubs 
  or 
  buckets, 
  the 
  

   spawn-taker 
  is 
  ready 
  to 
  take 
  the 
  eggs, 
  the 
  implements 
  necessary 
  being 
  

   a 
  feather 
  and 
  an 
  ordinary 
  milk-pan 
  coated 
  with 
  asphaltum 
  paint 
  on 
  the 
  

   inside 
  to 
  prevent 
  rust. 
  The 
  pan 
  is 
  first 
  dipped 
  in 
  water 
  and 
  allowed 
  

   to 
  drain, 
  leaving 
  only 
  the 
  water 
  that 
  clings 
  to 
  the 
  inside. 
  Taking 
  a 
  

   female 
  from 
  the 
  tub 
  she 
  is 
  held 
  as 
  quietly 
  as 
  possible 
  till 
  all 
  struggles 
  

   cease, 
  and 
  then 
  pressing 
  gently 
  with 
  the 
  thumb 
  and 
  forefinger 
  a 
  little 
  

   above 
  the 
  ventral 
  fins, 
  the 
  hand 
  is 
  passed 
  down 
  the 
  belly 
  to 
  the 
  oviduct, 
  

  

  