﻿LOBSTER 
  AND 
  CLAM 
  INVESTIGATIONS. 
  173 
  

  

  entered 
  one 
  of 
  the 
  bags 
  through 
  a 
  hole, 
  and 
  devoured 
  2,500 
  fry 
  in 
  a 
  

   single 
  night. 
  

  

  In 
  addition 
  to 
  the 
  destruction 
  by 
  living 
  enemies 
  the 
  young 
  lobster 
  

   is 
  also 
  likely 
  to 
  be 
  stranded 
  on 
  the 
  shore 
  by 
  the 
  wind 
  and 
  receding 
  

   tide. 
  

  

  In 
  coniinement, 
  although 
  the 
  fry 
  are 
  protected 
  more 
  or 
  less 
  com- 
  

   pletel}' 
  from 
  natural 
  enemies, 
  others 
  equally 
  destructive 
  are 
  encoun- 
  

   tered 
  and 
  have 
  proved 
  serious 
  obstacles 
  in 
  successful 
  lobster 
  culture, 
  

   but 
  the 
  experiments 
  encourage 
  the 
  belief 
  that 
  in 
  due 
  time 
  all 
  these 
  

   difficulties 
  will 
  be 
  removed. 
  

  

  RATE 
  OF 
  GROWTH. 
  

  

  The 
  growth 
  oi 
  the 
  lobster, 
  especially 
  during 
  the 
  larval 
  period, 
  is 
  

   dependent 
  on 
  two 
  factors, 
  namel}', 
  temperature 
  of 
  the 
  water 
  and 
  food 
  

   supply. 
  Other 
  things 
  being 
  equal, 
  the 
  colder 
  the 
  water 
  the 
  slower 
  

   the 
  development, 
  and 
  vice 
  versa. 
  This 
  is 
  shown 
  by 
  a 
  comparison 
  of 
  

   the 
  experiments 
  at 
  the 
  various 
  stations, 
  and 
  also 
  of 
  experiments 
  at 
  

   the 
  beginning 
  and 
  near 
  the 
  close 
  of 
  the 
  season. 
  For 
  example, 
  at 
  

   Orrs 
  Island 
  in 
  1900, 
  when 
  the 
  temperature 
  of 
  the 
  water 
  averaged 
  60^, 
  

   it 
  took 
  25 
  to 
  26 
  days 
  for 
  the 
  fry 
  to 
  reach 
  the 
  lobsterling 
  stage. 
  At 
  

   Wickford 
  at 
  the 
  same 
  time, 
  with 
  the 
  water 
  at 
  72°, 
  the 
  f 
  r}^ 
  were 
  only 
  

   10 
  to 
  12 
  days 
  in 
  passing 
  through 
  the 
  same 
  metamorphoses. 
  In 
  the 
  

   one 
  experiment 
  at 
  Annisquam, 
  where 
  the 
  water 
  temperature 
  reached 
  

   76^ 
  F., 
  the 
  lobsterling 
  stage 
  was 
  reached 
  in 
  10 
  days. 
  In 
  the 
  same 
  

   locality 
  development 
  is 
  slower 
  at 
  the 
  beginning 
  of 
  the 
  season 
  than 
  

   toward 
  the 
  close. 
  At 
  Woods 
  Hole 
  in 
  the 
  early 
  part 
  of 
  the 
  season, 
  20 
  

   to 
  25 
  days 
  were 
  required 
  for 
  the 
  f 
  r}- 
  to 
  pass 
  through 
  the 
  larval 
  stages, 
  

   while 
  later 
  12 
  to 
  11 
  days 
  were 
  sufficient. 
  The 
  same 
  holds 
  true 
  at 
  

   Wickford, 
  although 
  not 
  so 
  noticeably, 
  since 
  the 
  difference 
  in 
  tempera- 
  

   ture 
  is 
  not 
  so 
  great. 
  Sixteen 
  da^s' 
  time 
  was 
  necessary 
  for 
  the 
  frj^ 
  to 
  

   become 
  lobsterlings 
  in 
  the 
  first 
  experiment 
  in 
  1900. 
  Later 
  in 
  the 
  sea- 
  

   son 
  only 
  9 
  or 
  10 
  days 
  were 
  needed. 
  

  

  The 
  amount 
  of 
  food 
  the 
  lobster 
  receives 
  is 
  also 
  of 
  importance. 
  Fry 
  

   which 
  are 
  poorly 
  nourished, 
  if 
  they 
  live 
  for 
  any 
  considerable 
  length 
  of 
  

   time, 
  will 
  remain 
  in 
  the 
  first 
  stage 
  for 
  as 
  much 
  as 
  3 
  or 
  4 
  weeks. 
  

  

  To 
  obtain 
  an 
  environment 
  which 
  will 
  encourage 
  a 
  rapid 
  growth 
  is 
  

   the 
  all-important 
  factor 
  in 
  rearing 
  the 
  fr}^ 
  The 
  shorter 
  the 
  critical 
  

   period 
  the 
  greater 
  the 
  chance 
  of 
  surviving 
  it. 
  

  

  POSSIBILITY 
  OF 
  ECONOMIC 
  LOBSTER 
  CULTURE. 
  

  

  The 
  results 
  of 
  these 
  investigations 
  lead 
  to 
  the 
  belief 
  that 
  it 
  is 
  not 
  

   only 
  feasible 
  to 
  retain 
  the 
  lobsterlings 
  in 
  inclosures 
  until 
  they 
  reach 
  a 
  

   marketable 
  size, 
  but 
  that 
  such 
  an 
  undertaking 
  might 
  be 
  made 
  a 
  pro- 
  

   fitable 
  industry. 
  The 
  special 
  commission 
  confined 
  its 
  attention 
  chieflj" 
  

  

  