﻿182 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  cate 
  that 
  at 
  times 
  during 
  this 
  year 
  some 
  of 
  the 
  fry 
  were 
  troubled 
  with 
  

   a 
  growth 
  of 
  diatoms. 
  

  

  During 
  the 
  next 
  year, 
  1901, 
  an 
  apparatus 
  similar 
  to 
  that 
  already 
  

   described 
  in 
  this 
  paper 
  was 
  installed 
  at 
  Wickford 
  with 
  the 
  cooperation 
  

   of 
  the 
  U. 
  S. 
  Fish 
  Commission. 
  As 
  far 
  as 
  can 
  be 
  learned 
  very 
  little 
  

   trouble 
  was 
  experienced 
  from 
  the 
  growth 
  of 
  diatoms 
  during 
  the 
  year. 
  

   The 
  only 
  statement 
  in 
  regard 
  to 
  diatoms 
  in 
  the 
  report 
  of 
  the 
  Rhode 
  

   Island 
  fish 
  commission 
  for 
  1902 
  is 
  that 
  "at 
  certain 
  periods 
  during 
  the 
  

   summer 
  a 
  great 
  quantity 
  of 
  diatoms 
  and 
  other 
  small 
  organisms, 
  both 
  

   plant 
  and 
  animal, 
  are 
  caught 
  in 
  the 
  meshes 
  of 
  the 
  scrim 
  bags 
  and 
  there 
  

   accumulate 
  to 
  such 
  an 
  extent 
  that 
  the 
  circulation 
  of 
  the 
  water 
  is 
  often 
  

   interfered 
  with." 
  Nothing 
  is 
  said 
  about 
  their 
  presence 
  on 
  the 
  fry, 
  

   and 
  Doctor 
  Mead 
  states 
  that 
  they 
  were 
  not 
  sufficiently 
  abundant 
  to 
  be 
  

   noticeable. 
  

  

  During 
  1902 
  a 
  new 
  style 
  of 
  apparatus 
  was 
  installed 
  at 
  Wickford, 
  

   consisting 
  of 
  large 
  square 
  canvas 
  bags, 
  12 
  by 
  12 
  by 
  5 
  feet, 
  with 
  small 
  

   windows 
  of 
  copper 
  netting, 
  as 
  described 
  in 
  the 
  report 
  of 
  the 
  Rhode 
  

   Island 
  fish 
  commission 
  for 
  1903. 
  In 
  the 
  bottom 
  of 
  these 
  bags 
  fans 
  

   revolved 
  as 
  in 
  the 
  other 
  experiments. 
  Fr>^ 
  reared 
  in 
  these 
  bags 
  

   remained 
  clean 
  until 
  the 
  first 
  of 
  July, 
  while 
  during 
  the 
  same 
  summer 
  at 
  

   Woods 
  Hole 
  diatoms 
  were 
  abundant 
  on 
  the 
  fry 
  throughout 
  the 
  season. 
  

   A 
  few 
  fry 
  obtained 
  from 
  Wickford 
  on 
  June 
  30, 
  1902, 
  showed 
  a 
  very 
  

   few 
  Licmophora 
  tincta 
  and 
  some 
  Tahellaria 
  {St7'latella) 
  unipunctata^ 
  

   Navicula 
  sp., 
  Rhahdonema 
  araiatum 
  and 
  Rluihdonema 
  adriaticum^ 
  but 
  

   the 
  diatoms 
  were 
  not 
  sufiiciently 
  abundant 
  to 
  be 
  noticeable 
  to 
  the 
  naked 
  

   eye. 
  The 
  fry 
  infected 
  had 
  been 
  hatched 
  at 
  Woods 
  Hole 
  and 
  immedi- 
  

   ately 
  transferred 
  to 
  Wickford, 
  The 
  first 
  week 
  in 
  July 
  diatoms 
  began 
  

   to 
  be 
  abundant 
  on 
  some 
  of 
  the 
  fry 
  at 
  Wickford, 
  in 
  all 
  cases 
  the 
  first 
  

   affected 
  being 
  those 
  hatched 
  at 
  Woods 
  Hole, 
  which, 
  as 
  we 
  have 
  already 
  

   seen, 
  were 
  quite 
  badly 
  infected 
  before 
  leaving 
  the 
  hatching 
  jars 
  at 
  that 
  

   place. 
  Fry 
  hatched 
  and 
  reared 
  at 
  Wickford 
  did 
  not 
  begin 
  to 
  show 
  a 
  

   growth 
  of 
  diatoms 
  until 
  after 
  July 
  8, 
  1902. 
  The 
  same 
  species 
  were 
  

   present 
  on 
  the 
  fry 
  hatched 
  and 
  reared 
  at 
  Wickford 
  as 
  on 
  those 
  hatched 
  

   and 
  reared 
  at 
  Woods 
  Hole, 
  but 
  the 
  relative 
  abundance 
  of 
  the 
  different 
  

   species 
  varied, 
  as 
  is 
  shown 
  by 
  the 
  following 
  table, 
  which 
  gives 
  the 
  

   names 
  of 
  the 
  eight 
  most 
  abundant 
  species 
  found 
  on 
  the 
  fry 
  of 
  the 
  two 
  

   localities. 
  

  

  On 
  fry 
  hatched 
  and 
  reared 
  at 
  Woods 
  Hole: 
  

   Licmophora 
  tincta 
  Grunow. 
  

   Diatoma 
  hyalinum 
  Kiitzing. 
  

   Rhahdonema 
  arcuatum 
  (Lyngby) 
  Kiitzing. 
  

   Tahellaria 
  (Striatella) 
  nnipnnctata 
  Agardh. 
  

   Licmophora 
  flahellata 
  (Carmichnel) 
  Agardh. 
  

   Synedra 
  gallionii 
  Ehrenberg. 
  

   Synedra 
  affinis 
  Kiitzing. 
  

   Grammatophora 
  marina 
  (Lyngby) 
  Kiitzing. 
  

  

  