Coloration of reef organisms
column spacer Coloration of reef organisms
  hot buttons for colours section of Biology of Caribbean Coral Reefs website
This section deals with the function of colours. Topics of HOW COLOURS ARE CREATED and HOW COLOURS ARE PERCEIVED can be accessed via the icons.

Function of colours

  Functions of colours and colour patterns in reef animals mainly fall into two categories of SOCIAL and DEFENSE, one topic of the former, mating display, being considered here. Other social and defense topics can be found in their own sections. Most or all of these topics have been mentioned elsewhere in the BCCR but, by its nature, this section on FUNCTION OF COLOURS pulls them together in broad summary. A third category of OTHER: UV PROTECTION also has its own, short section.

Function of colours: social: mating display

seahorse dive leader for Biology of Caribbean Coral Reefs website photograph of spotfin butterflyfishes taken from a video

"Bright coloration in reef fishes is not usually sexually related, because in most species the sexes are identically coloured. For example, this is likely a mating pair of spotfin butterflyfishes, but as far as I know there is no way to tell the sexes. Let's follow this one for a know, maybe the black spot back there IS to help in following...!" - Turneffe Island, Belize. Video courtesy Andy Stockbridge, Belize.

NOTE Chaetodon ocellatus


  photographs of parrotfishes comparing colours of the sexes
In instances as discussed in the section above where coral-reef fishes differ in sexual colour, as in wrasses and parrotfishes, it may be that the bright colours play a role in whether a female is attracted to the terminal-phase male. However, if this is an additional function of coloration in these groups, it is a special one because most Caribbean reef fishes show no sex-related colour differences. DeLoach 1999 Reef fish behavior. New World Publ., Florida.
seahorse dive leader for Biology of Caribbean Coral Reefs website photograph of spotfin butterflyfishes taken from a video

Some species of fishes such as spotfin butterflyfishes commonly swim in pairs around the reef, but this individual seems to be on its own. - Key Largo 2005

NOTE Chaetodon ocellatus


photograph of a mating pair of four-eye butterflyfishes Chaetodon capistratus
A few types of reef fishes, for example, butterflyfishes, are monogamous; that is, they remain together for life and mate together exclusively.





Presumed monogamous pair of 4-eye
butterflyfishes Chaetodon capistratus 0.5X


photograph of a Christmas-tree nudibranch Learchis poica courtesy Anne Dupont, Floridaphotograph of nudibranch Paleo jubatus courtesy Anne Dupont, Florida
Is it possible that the bright coloration of these Caribbean nudibranchs is associated with mating display? Think about what you know about the life habits of nudibranchs, then CLICK HERE for the answer. Photographs courtesy Anne Dupont, Florida.

Christmas-tree nudibranch Learchis
crawling on a hydroid 2X

Nudibranch Paleo jubatus 1.5X


hot button for how colours are created part of BCCR hot button for how colours are perceived part of BCCR hot button for functions of colours part of BCCR