﻿22 
  PROPAGATION 
  OF 
  FKESH-WATER 
  MUSSELS. 
  

  

  Since 
  the 
  fish 
  is 
  very 
  active, 
  suitable 
  nets 
  must 
  be 
  used 
  to 
  prevent 
  

   injury. 
  Trammel 
  or 
  gill 
  nets, 
  or 
  seines 
  of 
  unsuitable 
  mesh, 
  would 
  be 
  

   fatal. 
  

  

  A 
  satisfactory 
  completion 
  of 
  the 
  investigation 
  of 
  the 
  parasitic 
  stage 
  

   in 
  Q. 
  ehena 
  will 
  probably 
  be 
  greatly 
  aided 
  by 
  gaining 
  more 
  thorough 
  

   knowledge 
  of 
  the 
  fish's 
  habits. 
  This 
  information 
  will, 
  of 
  course, 
  aid 
  

   also 
  in 
  determining 
  suitable 
  measures 
  for 
  insuring 
  the 
  increase 
  of 
  the 
  

   mussel. 
  

  

  Since 
  some 
  mussels, 
  as 
  the 
  mucket, 
  Lampsilis 
  ligamentina, 
  have 
  been 
  

   successfully 
  carried 
  through 
  on 
  more 
  than 
  one 
  species 
  of 
  fish, 
  the 
  pos- 
  

   sibility 
  of 
  finding 
  some 
  more 
  practical 
  host 
  in 
  this 
  case 
  has 
  been 
  kept 
  

   in 
  mind. 
  I 
  am 
  of 
  the 
  opinion 
  that 
  the 
  experiments 
  already 
  conducted 
  

   have 
  been 
  sufficiently 
  thorough 
  to 
  demonstrate 
  that 
  the 
  species 
  so 
  far 
  

   tried 
  are 
  unsuitable. 
  Chances 
  for 
  success 
  would 
  be 
  looked 
  for 
  in 
  

   closely 
  related 
  species. 
  The 
  only 
  really 
  common 
  species 
  in 
  this 
  

   locality 
  answering 
  these 
  requirements 
  is 
  the 
  gizzard 
  shad, 
  Dorosoma 
  

   cepedianum 
  (Le 
  Sueur). 
  Unfortunately 
  this 
  fish, 
  like 
  Pomolohus, 
  is 
  

   not 
  readily 
  kept 
  alive; 
  but 
  the 
  difficulties 
  may 
  not 
  be 
  insuperable. 
  

   I 
  have 
  seen 
  it 
  kept 
  alive 
  several 
  hours 
  in 
  the 
  laboratory 
  during 
  the 
  

   winter 
  and 
  have 
  no 
  doubt 
  it 
  could 
  be 
  kept 
  in 
  ponds, 
  as 
  it 
  is 
  found 
  

   alive 
  in 
  bayous 
  isolated 
  from 
  the 
  river. 
  As 
  it 
  has 
  not 
  yet, 
  however, 
  

   been 
  found 
  to 
  carry 
  mussels 
  upon 
  the 
  gills, 
  the 
  probabilities 
  of 
  success 
  

   are 
  quite 
  uncertain. 
  

  

  Three 
  species 
  of 
  shad 
  are 
  found 
  in 
  the 
  Mississippi. 
  These 
  are 
  more 
  

   closely 
  related 
  to 
  Pomolohus, 
  but 
  they 
  are 
  not 
  reported 
  common 
  

   north 
  of 
  St. 
  Louis. 
  Surber 
  (1913) 
  suggests 
  the 
  interesting 
  experi- 
  

   ment 
  of 
  infecting 
  the 
  species 
  of 
  herring 
  to 
  be 
  found 
  in 
  the 
  rivers 
  of 
  the 
  

   Atlantif* 
  coast. 
  This 
  might 
  be 
  successful 
  if 
  tried 
  in 
  rivers 
  containing 
  

   considerable 
  lime 
  in 
  solution, 
  as 
  is 
  the 
  case 
  in 
  the 
  rivers 
  in 
  which 
  the 
  

   niggerhead 
  thrives. 
  

  

  Propagation. 
  — 
  There 
  is 
  probably 
  no 
  shell 
  for 
  which 
  there 
  is 
  a 
  larger 
  

   demand 
  at 
  present 
  and 
  its 
  uses 
  might 
  be 
  greatly 
  increased. 
  From 
  

   the 
  results 
  already 
  attained 
  in 
  the 
  investigation 
  of 
  the 
  life 
  history 
  of 
  

   the 
  niggerhead, 
  propagation 
  might 
  be 
  undertaken 
  at 
  once, 
  provided 
  

   it 
  were 
  done 
  in 
  a 
  way 
  that 
  would 
  permit 
  of 
  definitely 
  ascertaining 
  

   results. 
  Whether 
  the 
  herring 
  can 
  be 
  caught 
  in 
  sufficient 
  numbers 
  

   to 
  make 
  such 
  operations 
  practicable 
  is 
  a 
  question, 
  but 
  reports 
  would 
  

   indicate 
  that 
  they 
  can 
  be 
  in 
  some 
  localities. 
  However, 
  operations 
  

   upon 
  a 
  large 
  scale 
  are 
  hardly 
  to 
  be 
  recommended 
  before 
  a 
  demon- 
  

   stration 
  of 
  artificial 
  infection 
  and 
  the 
  completion 
  of 
  the 
  parasitic 
  

   period 
  has 
  been 
  observed. 
  

  

  The 
  remarkably 
  full 
  infection, 
  of 
  this 
  species 
  in 
  nature 
  indicate 
  that 
  

   under 
  natural 
  conditions 
  propagation 
  of 
  this 
  mussel 
  will 
  take 
  care 
  of 
  

   itself. 
  Thus 
  recommendations 
  of 
  measures 
  for 
  preventing 
  the 
  deple- 
  

   tion 
  of 
  thfj 
  niggerhead 
  would 
  be 
  along 
  the 
  line 
  of 
  protection 
  to 
  the 
  

  

  