Ruby on Rails: uninitialized constant, NameError

Hello I am trying to solve a name error in a RAILS application. I am working on an interface which consists in a map with tiles associated to a certain number of projects.

I have the following models: area.rb

class Area < ActiveRecord::Base
  attr_accessible :map_file_name, :tile_file_name, :alt, ...

  has_many :species
  has_many :maps

end

map.rb,

class Map < ActiveRecord::Base
  attr_accessible :alt, :file_name, :detail, :area_id

  belongs_to :area
end

and specie.rb

class Specie < ActiveRecord::Base
  attr_accessible :area_id, :author_id, :name, :pwclass, :pwfamily, :txtlandscape, :txtpod, :map

  has_one :author
  belongs_to :area

end

When I try to call the resource in IRB or in a view I get the name error output. I changed specie to field and species to fields, and it works with the same configuration.

I checked and Ruby pluralises specie correctly to species.

How can I get specie to work?

UPDATE : backtrace

Started GET "/projects/show/1" for 127.0.0.1 at Fri Mar 23 13:02:07 +0100 2018
Connecting to database specified by database.yml
Processing by ProjectsController#show as HTML
  Parameters: {"id"=>"1"}
  [1m[36mArea Load (1.8ms)[0m  [1mSELECT 'areas'.* FROM 'areas' WHERE 'areas'.'id' = ? LIMIT 1[0m  [["id", "1"]]
  [1m[35mMap Load (0.4ms)[0m  SELECT 'maps'.* FROM 'maps' WHERE 'maps'.'area_id' = 1
  Rendered projects/show.html.erb (28.1ms)
Completed 500 Internal Server Error in 108ms

ActionView::Template::Error (uninitialized constant Area::Species):
    28:         end %>
    29: <% else %>
    30: <% end %>
    31: <% for specie in @area.species %>
    32: <div class="speciesmap">
    33:   <div id="tile_menu">
    34:     <a onclick="ArticleRequest('/article/show/area-07.html', 'ATLAS-06');"><img src="images/MAP/GUADALQUIVIR_MAP-BUTTONS-TILE-specie.svg" onMouseOver="this.src='images/MAP/estuario_area_136x85px-blck.svg'" onMouseOut="this.src='images/MAP/GUADALQUIVIR_MAP-BUTTONS-TILE-specie.svg'" alt="Specie"></a>
  app/views/projects/show.html.erb:31:in '_app_views_projects_show_html_erb__1608931551_2294133420'
  app/controllers/projects_controller.rb:22:in `show'


  Rendered /Users/xxx/.rvm/gems/ruby-1.8.7-p374@ccc/gems/actionpack-3.2.5/lib/action_dispatch/middleware/templates/rescues/_trace.erb (0.7ms)
  Rendered /Users/xxx/.rvm/gems/ruby-1.8.7-p374@ccc/gems/actionpack-3.2.5/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (0.6ms)
  Rendered /Users/xxx/.rvm/gems/ruby-1.8.7-p374@ccc/gems/actionpack-3.2.5/lib/action_dispatch/middleware/templates/rescues/template_error.erb within rescues/layout (40.4ms)