﻿MANUAL 
  OF 
  FISH-CULTURE. 
  237 
  

  

  HATCHING 
  APPARATUS 
  AND 
  OPERATIONS. 
  

  

  Experiraeiits 
  conducted 
  during- 
  ;i 
  series 
  of 
  years 
  having 
  demonstrated 
  

   that 
  the 
  automatic 
  hatching-Jar 
  was 
  the 
  best 
  form 
  of 
  ai>]»aratus 
  for 
  

   hatching 
  lobster 
  eggs, 
  it 
  has 
  been 
  adopted 
  at 
  the 
  stations 
  of 
  the 
  Com- 
  

   mission 
  since 
  1889. 
  A 
  full 
  description 
  of 
  this 
  jar 
  is 
  given 
  in 
  the 
  article 
  

   on 
  shad-culture, 
  pp. 
  150-152. 
  The 
  manipulation 
  and 
  operation 
  of 
  the 
  jar 
  

   is 
  i)ractically 
  the 
  same 
  as 
  with 
  shad 
  eggs, 
  except 
  that 
  frequently, 
  where 
  

   the 
  water 
  supply 
  is 
  inadequate, 
  three 
  jars 
  are 
  connected 
  by 
  means 
  of 
  

   rubber 
  tubing 
  and 
  the 
  water 
  used 
  over 
  and 
  over. 
  This 
  is 
  accomplished 
  

   by 
  connecting 
  the 
  overflow 
  from 
  the 
  first 
  jar 
  with 
  the 
  supply 
  to 
  the 
  

   second 
  and 
  so 
  on, 
  but 
  can 
  only 
  be 
  done 
  during 
  the 
  early 
  stages 
  before 
  

   the 
  fry 
  commence 
  to 
  hatch. 
  When 
  first 
  placed 
  in 
  the 
  jar 
  the 
  eggs 
  are 
  

   matted 
  together 
  by 
  the 
  fine 
  hair-like 
  fibers, 
  but 
  after 
  a 
  few 
  days 
  they 
  

   separate 
  and 
  work 
  very 
  much 
  like 
  shad 
  eggs. 
  

  

  From 
  400,000 
  to 
  500,000 
  eggs 
  (equivalent 
  to 
  about 
  2 
  to 
  2i 
  quarts) 
  are 
  

   usually 
  placed 
  in 
  each 
  jar, 
  although 
  at 
  times 
  when 
  the 
  hatchery 
  is 
  

   crowded 
  a 
  few 
  more 
  may 
  be 
  successfully 
  cared 
  for. 
  

  

  The 
  fry 
  pass 
  voluntarily 
  from 
  these 
  jars 
  to 
  cylindrical 
  glass 
  jars, 
  9 
  

   inches 
  in 
  diameter 
  and 
  either 
  9 
  or 
  18 
  inches 
  high, 
  placed 
  in 
  the 
  center 
  

   of 
  the 
  table 
  and 
  covered 
  with 
  cheese-cloth 
  at 
  the 
  top 
  to 
  i)revent 
  their 
  

   escape. 
  

  

  The 
  i^eriod 
  of 
  incubation 
  depends 
  entirely 
  upon 
  the 
  age 
  of 
  the 
  egg 
  

   when 
  collected. 
  For 
  example, 
  eggs 
  taken 
  in 
  October 
  do 
  not 
  hatch 
  until 
  

   the 
  following 
  May, 
  whereas 
  eggs 
  collected 
  in 
  June 
  frecpieutly 
  hatch 
  

   in 
  24 
  hours 
  after 
  being 
  placed 
  in 
  the 
  jars. 
  During 
  one 
  season 
  eggs 
  

   collected 
  from 
  December 
  12 
  to 
  January 
  25, 
  numbering 
  1,717,000, 
  at 
  a 
  

   temperature 
  of 
  45°, 
  commenced 
  hatching 
  May 
  25 
  at 
  a 
  temperature 
  of 
  

   54°. 
  To 
  determine 
  how 
  soon 
  the 
  new-laid 
  eggs 
  can 
  be 
  taken 
  from 
  the 
  

   parent 
  and 
  hatched 
  artificially, 
  collections 
  were 
  begun 
  early 
  in 
  July 
  

   and 
  continued 
  until 
  fall, 
  for 
  several 
  seasons, 
  the 
  eggs 
  being 
  i^laced 
  in 
  

   hatching-jars 
  at 
  the 
  AVoods 
  Hole 
  Station; 
  all 
  those 
  collected 
  j^rior 
  to 
  

   October 
  15 
  died. 
  In 
  November, 
  1895, 
  15,000,000 
  were 
  placed 
  in 
  jars 
  

   and 
  carried 
  through 
  the 
  winter 
  under 
  very 
  unfavorable 
  conditions, 
  but 
  

   hatched 
  with 
  a 
  loss 
  of 
  only 
  50 
  i)er 
  cent. 
  The 
  density 
  of 
  the 
  water 
  at 
  

   Woods 
  Hole 
  varies 
  from 
  1.023 
  to 
  1.025, 
  its 
  average 
  temperature 
  being 
  

   from 
  49° 
  to 
  04° 
  during 
  the 
  months 
  of 
  April, 
  May, 
  and 
  June. 
  

  

  THE 
  LOBSTER 
  FRY. 
  

  

  Owing 
  to 
  the 
  cannibalistic 
  habits 
  of 
  young 
  lobsters 
  when 
  closely 
  

   crowded, 
  it 
  has 
  been 
  the 
  policy 
  of 
  the 
  Commission 
  to 
  liberate 
  the 
  fry 
  

   as 
  soon 
  after 
  hatching 
  as 
  possible. 
  They 
  are 
  taken 
  out 
  in 
  ordinary 
  

   10-gallon 
  transportation 
  cans, 
  about 
  200,000 
  being 
  placed 
  in 
  a 
  can 
  for 
  

   short 
  shipments 
  and 
  125,000 
  for 
  long 
  shipments, 
  and 
  liberated 
  iu 
  the 
  

   vicinity 
  of 
  the 
  grounds 
  from 
  which 
  the 
  adult 
  lobsters 
  were 
  taken. 
  

   When 
  this 
  is 
  impracticable, 
  they 
  are 
  liberated 
  iu 
  Vineyard 
  Sound 
  and 
  

   Buzzards 
  Bay 
  with 
  an 
  outgoing 
  tide, 
  so 
  as 
  to 
  insure 
  their 
  wide 
  distri- 
  

  

  