﻿THE 
  RAINBOW 
  TROUT. 
  

  

  DESCRIPTION 
  OF 
  THE 
  FISH. 
  

  

  The 
  body 
  of 
  the 
  rainbow 
  trout 
  {Salmo 
  irideus) 
  is 
  comparatively 
  short 
  

   and 
  deep, 
  and 
  is 
  more 
  elongate 
  in 
  males 
  than 
  in 
  females. 
  The 
  average 
  

   depth 
  is 
  contained 
  about 
  three 
  and 
  four-fifths 
  times 
  in 
  the 
  body 
  length. 
  

   The 
  short 
  head, 
  which 
  is 
  obtusely 
  ridged 
  above, 
  is 
  about 
  one-fourth 
  the 
  

   total 
  length. 
  The 
  mouth 
  is 
  smaller 
  than 
  in 
  other 
  species 
  of 
  Salmo, 
  the 
  

   maxillary 
  reaching 
  scarcely 
  beyond 
  the 
  eye, 
  which 
  is 
  rather 
  large, 
  and 
  

   is 
  contained 
  five 
  times 
  in 
  the 
  side 
  of 
  the 
  head. 
  The 
  caudal 
  fin 
  is 
  dis 
  

   tinctly 
  but 
  not 
  strongly 
  forked. 
  On 
  the 
  vomer 
  are 
  two 
  irregular 
  series 
  

   of 
  teeth. 
  The 
  dorsal 
  rays 
  number 
  11 
  and 
  the 
  anal 
  10. 
  In 
  the 
  typical 
  

   species 
  there 
  are 
  about 
  135 
  scales 
  in 
  the 
  lateral 
  series, 
  with 
  20 
  rows 
  

   above 
  and 
  20 
  below 
  the 
  lateral 
  line; 
  in 
  the 
  several 
  subspecies 
  the 
  

   number 
  of 
  rows 
  of 
  scales 
  along 
  the 
  side 
  is 
  from 
  120 
  to 
  180. 
  The 
  color 
  is 
  

   variable, 
  depending 
  on 
  sex, 
  age, 
  and 
  character 
  of 
  water. 
  Typical 
  adult 
  

   fish 
  are 
  bluish 
  above, 
  silvery 
  on 
  the 
  sides, 
  profusely 
  and 
  irregularly 
  

   dark-spotted 
  on 
  the 
  back 
  and 
  sides, 
  the 
  spots 
  extending 
  to 
  the 
  vertical 
  

   fins, 
  with 
  a 
  red 
  lateral 
  band 
  and 
  blotches 
  and 
  a 
  nearly 
  plain 
  belly. 
  The 
  

   sea-run 
  fish 
  are 
  nearly 
  plain 
  silvery. 
  The 
  chief 
  distinguishing 
  color 
  

   characteristics 
  of 
  the 
  varieties 
  are 
  in 
  the 
  number 
  and 
  position 
  of 
  the 
  

   spots. 
  

  

  RANGE 
  AND 
  VARIATION. 
  

  

  The 
  rainbow 
  trout 
  is 
  not 
  indigenous 
  to 
  eastern 
  waters, 
  its 
  original 
  

   habitat 
  being 
  the 
  Pacific 
  coast 
  of 
  the 
  United 
  Stales. 
  It 
  is 
  especially 
  

   abundant 
  in 
  the 
  mountain 
  streams 
  of 
  California. 
  A 
  few 
  specimens, 
  

   however, 
  have 
  been 
  taken 
  in 
  saltwater, 
  and 
  it 
  is 
  not 
  unlikely 
  that 
  some 
  

   find 
  their 
  way 
  through 
  the 
  rivers 
  into 
  the 
  sea. 
  

  

  The 
  species 
  is 
  subject 
  to 
  considerable 
  variation 
  in 
  form 
  and 
  color 
  in 
  

  

  different 
  parts 
  of 
  its 
  range, 
  and 
  the 
  following 
  varieties 
  have 
  received 
  

  

  recognition 
  by 
  ichthyologists: 
  The 
  brook 
  trout 
  of 
  western 
  Oregon 
  and 
  

  

  Washington 
  {Salmo 
  irideus 
  masoni), 
  which 
  rarely 
  weighs 
  as 
  much 
  as 
  a 
  

  

  pound 
  and 
  is 
  locally 
  abundant 
  in 
  the 
  streams 
  of 
  the 
  Coast 
  Eaugefrom 
  

  

  Paget 
  Sound 
  to 
  southern 
  Oregon; 
  the 
  McCloud 
  River 
  trout 
  {Salmo 
  

  

  irideus 
  shasta), 
  which 
  attains 
  a 
  large 
  size, 
  is 
  abuiulant 
  in 
  the 
  streams 
  of 
  

  

  the 
  Sierra 
  Nevada 
  Mountains 
  from 
  Mount 
  Shasta 
  southward, 
  and 
  is 
  the 
  

  

  rainbow 
  trout 
  which 
  has 
  received 
  most 
  attention 
  from 
  fishculturists; 
  

  

  the 
  Kern 
  River 
  trout 
  {Saliuo 
  irideus 
  gilberti), 
  which 
  attains 
  a 
  Aveight 
  of 
  

  

  8 
  pounds, 
  and 
  is 
  found 
  only 
  in 
  Kern 
  River, 
  California; 
  the 
  noshee 
  or 
  

  

  nissuee 
  trout 
  {Salmo 
  irideus 
  stonei), 
  which 
  inhabits 
  the 
  Sacramento 
  

  

  basin, 
  and 
  reaches 
  a 
  weight 
  of 
  12 
  pounds; 
  the 
  golden 
  trout 
  of 
  Mount 
  

  

  Whitney 
  {Salmo 
  irideus 
  aquabonita), 
  which 
  inhabits 
  streams 
  on 
  both 
  

  

  sides 
  of 
  Mount 
  Whitney, 
  California. 
  

  

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