﻿III. 
  THE 
  CAUSES 
  OF 
  DEATH 
  IN 
  ARTIFICIALLY-REARED 
  

   LOBSTER 
  FRY. 
  

  

  By 
  Frederic 
  P. 
  Gorham, 
  

   Associate 
  Professor 
  of 
  Biology, 
  Brown 
  University. 
  

  

  Attempts 
  to 
  rear 
  lobster 
  fry 
  through 
  the 
  first 
  three 
  stages 
  of 
  

   development 
  under 
  artificial 
  conditions 
  have 
  been 
  attended 
  by 
  many 
  

   dilHculties. 
  Although 
  protected 
  from 
  most 
  of 
  their 
  enemies 
  when 
  

   kept 
  in 
  confinement, 
  the 
  fry 
  are 
  still 
  subject 
  to 
  attacks 
  of 
  various 
  

   kinds, 
  and 
  the 
  elimination 
  of 
  these 
  destructive 
  agents 
  must 
  be 
  accom- 
  

   plished 
  before 
  complete 
  success 
  in 
  lobster 
  culture 
  can 
  be 
  attained. 
  

   Cannibalism 
  was 
  one 
  of 
  the 
  mo^t 
  conspicuous 
  causes 
  of 
  loss 
  in 
  the 
  

   early 
  experiments, 
  and 
  an 
  abundant 
  growth 
  of 
  diatoms, 
  other 
  algas, 
  

   and 
  protozoa, 
  covering 
  the 
  bodies 
  and 
  appendages 
  and 
  interfering 
  

   with 
  movement 
  and 
  feeding, 
  has 
  destroyed 
  large 
  numbers 
  throughout 
  

   the 
  progress 
  of 
  the 
  work. 
  A 
  fatal 
  fungus 
  which 
  attacks 
  them 
  has 
  also 
  

   l)een 
  a 
  factor 
  difficult 
  to 
  contend 
  with. 
  

  

  During 
  the 
  summer 
  of 
  1902, 
  at 
  the 
  request 
  of 
  Dr. 
  Hugh 
  M. 
  Smith, 
  

   then 
  chief 
  of 
  the 
  division 
  of 
  scientific 
  inquiry 
  of 
  the 
  U. 
  S. 
  Fish 
  

   Commission, 
  I 
  undertook 
  the 
  study 
  of 
  these 
  causes 
  of 
  death 
  in 
  

   lobster 
  fry, 
  with 
  a 
  view 
  to 
  suggesting 
  remedial 
  measures. 
  Observa- 
  

   tions 
  were 
  begun 
  as 
  soon 
  as 
  the 
  experimental 
  hatching 
  and 
  rearing 
  

   plant 
  at 
  Woods 
  Hole 
  was 
  installed. 
  This 
  apparatus 
  was 
  operated 
  

   under 
  the 
  direction 
  of 
  the 
  special 
  commission 
  for 
  the 
  investigation 
  of 
  

   the 
  lobster 
  and 
  clam, 
  and 
  is 
  described 
  in 
  detail 
  elsewhere 
  in 
  this 
  

   report. 
  

  

  CANNIBALISM. 
  

  

  The 
  first 
  fry 
  were 
  placed 
  in 
  the 
  bags 
  May 
  19, 
  1902, 
  but 
  the 
  fans 
  

   were 
  not 
  set 
  in 
  motion 
  until 
  June 
  3. 
  Cannibalism 
  was 
  especially 
  

   niarked 
  when 
  the 
  fr}^ 
  were 
  in 
  crowded 
  quarters 
  or 
  were 
  allowed 
  to 
  

   collect 
  in 
  corners. 
  It 
  was 
  evident 
  that 
  they 
  must 
  be 
  kept 
  in 
  a 
  recep- 
  

   tacle 
  large 
  enough 
  to 
  allow 
  each 
  individual 
  considerable 
  space 
  to 
  him- 
  

   self; 
  otherwise, 
  if 
  the\^did 
  not 
  devour 
  each 
  other, 
  they 
  suttocated 
  and 
  

   l)ecame 
  foul. 
  Moreover, 
  the}^ 
  must 
  be 
  supplied 
  with 
  an 
  attractive 
  

   food 
  with 
  such 
  frequency 
  that 
  thev 
  were 
  not 
  tempted 
  to 
  feed 
  upon 
  each 
  

   other. 
  

  

  The 
  first 
  tw^o 
  of 
  these 
  conditions, 
  plenty 
  of 
  room 
  and 
  continual 
  

   motion, 
  are 
  well 
  met 
  by 
  the 
  rearing 
  apparatus 
  used 
  by 
  the 
  special 
  com- 
  

   mission. 
  The 
  third 
  — 
  that 
  of 
  food 
  supply 
  — 
  requires 
  further 
  attention, 
  

  

  175 
  

  

  