Diagonal butterflyfish

[Tom Hourigan]

Dear Roi,

I assume that you are referring to Chaetodon fasciatus? (C. auriga, the
threadfin butterflyfish, is also sometimes referred to as the diagonal
butterflyfish).

I have not observed C. fasciatus, but its coloration (dark yellows with
black and bright white patches) is reminiscent of C. lunula and C.
quadrimaculatus.  The contrasting black and white is thought to increase
visibility in low light situations.  Hobson (1974 - Fish Bull. 72:915-1031)
presented gut content evidence that C. lunula fed at least to some extent at
night in Hawaii.  My own work on C. quadrimaculatus (Hourigan 1986, 1987)
showed that this species fed on a lunar day rather than on a solar day in
Hawaii.  During the new moon, pairs fed primarily during the day, with the
onset of feeding shifting about 50 minutes later on subsequent days, so that
by the time of the full moon they were sheltered most of the day and feeding
at night!  This is the only example of such an unusual diel cycle for a
coral reef fish of which I am aware. C. quadrimaculatus, like C. fasciatus
forms pairs and feeds in part on coral polyps. C. lunula in Hawaii, in
contrast does not seem to form pairs or feed on corals.

It is interesting that the permanent coloration of C. quadrimaculatus is
very similar to the temporary nocturnal coloration of several butterflyfish
species (e.g., Chaetodon citrinellus, C. melanotus, C.  tinkeri and C.
trifascialis).  I would be very interested to learn if C. fasciatus is
feeding at least partially at night.

Tom


Hourigan, T.F. (1987).  The Behavioral Ecology of Three Species of Hawaiian
  Butterflyfishes, (Fam. Chaetodontidae).  Ph.D. Dissertation, University of
Hawaii.

Hourigan, T.F. (1986).  An experimental removal of a territorial
pomacentrid: Effects
  on the occurrence and behavior of competitors.  Env. Biol. Fish.
15(3):161-169.

Roi Holzman wrote:

> hallow alldoes anybody knows a reference on the diel behavior and activity
> of the above fish or a similar butterflyfish ?
>
> thanks in advanceRoi Holzman
> roi at pob.huji.ac.il
> InterUniversity Institute For Marine Science of Eilat
> P.O. box 469, Eilat, 88103, Israel.
> Phone: 972-8-6360129/143
> Fax: 972-8-6374329

  Thomas F. Hourigan, Ph.D. <Tom.Hourigan at noaa.gov>
  Coral Reef and Biodiversity Coordinator
  Office of Habitat Conservation -- Tel: (301) 713-2319
  NOAA/National Marine Fisheries Service -- Fax: (301) 713-0376

  Thomas F. Hourigan, Ph.D.
  Coral Reef and Biodiversity Coordinator          <Tom.Hourigan at noaa.gov>
  Office of Habitat Conservation -- Tel: (301)
  713-2319
  NOAA/National Marine Fisheries Service -- Fax:
  (301) 713-0376
  1315 East-West Highway                           Fax: (301) 713-0376
  Silver Spring                                    Work: (301) 713-2319
  MD
  20850
  U.S.A.
  Additional Information:
  Last Name    Hourigan
  First Name   Tom
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