﻿MANUAL 
  OF 
  FISH 
  CULTURE. 
  191 
  

  

  viscid 
  ill 
  about 
  20 
  minutes 
  after 
  fertilization 
  and 
  stick 
  together 
  in 
  

   masses 
  of 
  various 
  sizes. 
  This 
  interferes 
  with 
  their 
  aeration, 
  lowers 
  the 
  

   vitality, 
  and 
  leads 
  to 
  the 
  attack 
  of 
  fungus. 
  The 
  practice 
  heretofore 
  

   adopted 
  for 
  overcoming 
  this 
  condition 
  has 
  been 
  either 
  to 
  spread 
  the 
  eggs 
  

   in 
  very 
  thin 
  layers 
  on 
  the 
  hatching 
  trays 
  prior 
  to 
  the 
  development 
  of 
  

   the 
  adhesive 
  quality, 
  so 
  that 
  after 
  becoming 
  fixed 
  they 
  wonld 
  be 
  properly 
  

   aerated, 
  or 
  to 
  stir 
  them 
  continuously 
  for 
  several 
  hours 
  in 
  order 
  to 
  over- 
  

   come 
  their 
  adhesiveness. 
  The 
  high 
  degree 
  of 
  success 
  attending 
  the 
  

   hatching 
  of 
  the 
  glutinous 
  eggs 
  of 
  the 
  flatfish 
  and 
  the 
  wall-eyed 
  pike 
  

   indicates 
  that 
  the 
  difiiculty 
  encountered 
  with 
  the 
  similar 
  sturgeon 
  egg 
  

   may 
  be 
  readily 
  overcome. 
  By 
  gently 
  stirring 
  recently 
  fertilized 
  eggs 
  

   with 
  a 
  mixture 
  of 
  dry 
  cornstarch 
  and 
  water 
  or 
  fine 
  swamp 
  muck 
  and 
  

   water, 
  the 
  tendency 
  of 
  the 
  eggs 
  to 
  stick 
  together 
  and 
  to 
  other 
  objects 
  

   is 
  avoided 
  through 
  the 
  partial 
  coating 
  of 
  the 
  individual 
  eggs 
  with 
  

   particles 
  of 
  starch 
  or 
  dirt. 
  Other 
  substances 
  that 
  will 
  remain 
  suspended 
  

   and 
  not 
  be 
  dissolved 
  in 
  water 
  can 
  doubtless 
  be 
  employed 
  to 
  advantage. 
  

   Swamp 
  muck 
  is 
  jirobably 
  the 
  best, 
  because 
  cheapest 
  and 
  most 
  easily 
  

   obtained; 
  2 
  quarts 
  of 
  it 
  may 
  be 
  mixed 
  with 
  10 
  gallons 
  of 
  water, 
  which 
  

   will 
  be 
  sufficient 
  to 
  render 
  non-glutinous 
  about 
  3 
  gallons 
  of 
  eggs; 
  the 
  

   same 
  proportion 
  of 
  water, 
  eggs, 
  and 
  cornstarch 
  is 
  recommended. 
  After 
  

   being 
  transferred 
  to 
  the 
  hatching 
  station, 
  the 
  eggs 
  may 
  be 
  placed 
  under 
  

   running 
  water 
  and 
  the 
  superfluous 
  foreign 
  particles 
  washed 
  away 
  before 
  

   being 
  placed 
  in 
  the 
  hatching 
  apparatus. 
  

  

  The 
  apparatus 
  used 
  in 
  hatching 
  sturgeon 
  eggs 
  has 
  been 
  chiefly 
  boxes 
  

   placed 
  in 
  the 
  open 
  water 
  of 
  the 
  river. 
  The 
  giutinosity 
  being 
  overcome, 
  

   there 
  seems 
  no 
  reason 
  why 
  hatching 
  may 
  not 
  be 
  conducted 
  in 
  the 
  auto- 
  

   matic 
  shad 
  jar 
  or 
  in 
  other 
  modern 
  appliances. 
  

  

  In 
  the 
  experimental 
  hatching 
  operations 
  many 
  eggs 
  have 
  been 
  lost 
  

   through 
  attacks 
  of 
  fungus, 
  induced 
  by 
  the 
  character 
  of 
  the 
  apparatus 
  

   employed. 
  The 
  use 
  of 
  floating-boxes 
  in 
  open 
  water 
  has 
  led 
  to 
  the 
  loss 
  

   of 
  eggs 
  by 
  storms, 
  rough 
  water, 
  and 
  sudden 
  changes 
  of 
  temperature. 
  

  

  The 
  incubation 
  period 
  is 
  about 
  7 
  days 
  in 
  water 
  having 
  a 
  temperature 
  

   of 
  02° 
  to 
  GOO 
  r. 
  The 
  outline 
  of 
  the 
  fish 
  appears 
  in 
  48 
  hours. 
  

  

  The 
  question 
  as 
  to 
  whether 
  eggs 
  of 
  the 
  common 
  sturgeon 
  can 
  best 
  

   be 
  hatched 
  in 
  fresh 
  or 
  brackish 
  water 
  is 
  not 
  yet 
  determined, 
  but 
  the 
  

   indications 
  are 
  that 
  bra(;kish 
  water 
  is 
  preferable. 
  One 
  reason 
  is 
  that 
  

   the 
  eggs 
  are 
  less 
  liable 
  to 
  attacks 
  of 
  fungus 
  in 
  such 
  water. 
  

  

  An 
  attempt 
  to 
  rear 
  artificially 
  hatched 
  sturgeon 
  at 
  North 
  ville 
  was 
  

   unsuccessful, 
  owing 
  to 
  the 
  failure 
  of 
  the 
  young 
  to 
  eat. 
  The 
  mouth 
  of 
  

   the 
  sturgeon 
  fry 
  is 
  very 
  small, 
  and 
  the 
  food 
  is 
  largely 
  of 
  a 
  microscopic 
  

   character, 
  consisting 
  of 
  unicellular 
  alga^, 
  infusoria, 
  insect 
  larvte, 
  etc. 
  

  

  In 
  Europe, 
  where 
  the 
  sturgeon 
  fisheries 
  are 
  vastly 
  more 
  important 
  than 
  

   in 
  America, 
  the 
  results 
  of 
  experiments 
  in 
  sturgeon-culture 
  have 
  scarcely 
  

   been 
  as 
  satisfactory 
  as 
  in 
  this 
  country. 
  No 
  method 
  of 
  separating 
  gluti- 
  

   nous 
  eggs 
  except 
  by 
  stirring 
  seems 
  to 
  have 
  been 
  devised, 
  and 
  the 
  same 
  

   difficulty 
  has 
  been 
  found 
  in 
  obtaining 
  fish 
  with 
  ripe 
  spawn 
  and 
  milt. 
  

   The 
  retention 
  of 
  fish 
  in 
  inclosures 
  has 
  not 
  generally 
  been 
  successful. 
  

  

  