[Coral-List] Re: Coryphopterus personatus feeding habits

[Jim Bohnsack]

Edwin, We see orders of magnitude variance in masked goby abudances in
the Keys from year to year also.  The most simple explanation, I
believe, is recruitment variability - possibly due to oceanographic
conditions and chance factors.  I find it hard to believe that benthos
colonization or change has much to do with it.   As far as I know, the
masked goby is a planktivore.

Hernandez Edwin wrote:

> Dear coral_listers and other colleages:
>
> I've been writing a manuscript about the results of
> our long-term monitoring studies of reef fish
> communities within the Luis Pena Channel No-Take
> Natural Reserve, in Culebra Island, Puerto Rico. We
> have found interesting results comparing data from the
> 3 years before the reserve designation to the
> following 4 years.  There has been a significant
> recovery of many of the fishery target species,
> including piscivore groups.
>
> However, we've found an unexpected up to 10-fold
> increase in the population density of the masked goby,
> Coryphopterus personatus (Gobiidae), particularly
> during the last 2 years. This is coincident with a
> major decline in coral cover and a major increase in
> macroalgal and cyanobacterial cover (Hernandez-Delgado
> and Sabat, in review).
>
> I'm wondering if this bloom in the masked gobies
> population is habitat-related (i.e., increased food
> supply).  Many gobiid species are omnivorous, thus
> algae and detritus are part of their diet (Randall,
> 1967).  I'm suggesting that, besides successful
> recruitment cycles, population increases could be the
> result of increased food supplies as a result of
> increased algal overgrowth and the subsequent
> increased production of detritus.
>
> However, I have not been able to find any single
> reference about the feeding habits, stomach contents,
> or similar information about Coryphopterus personatus.
>
> Also, C. personatus is a benthic spawner with external
> fertilization. However, I'm not sure what is their
> preferred spawning habitat, although I think that reef
> crevices could be.  Then I guess that another
> explanation to their apparent recent success could be
> related to increased microhabitat tridimentionality
> provided by macroalgal and turf canopies.
>
> I've browsed FishBase, my personal library, and as
> many other sources available.
>
> I'd like to have some light on any reference
> regarding:
>
> 1. Feeding habits.
> 2. Reproductive frequency.
> 3. Preferred spawning habitat.
>
> Also, will appreciate if anybody else has long-term
> data regarding the population dynamics of this
> species.
>
> Thanks in advance!
>
> Saludos desde Puerto Rico.
>
> Edwin A. Hernandez, Ph.D.
> Coral Reef Long-Term Ecological Monitoring and
> Restoration Program
> 180 Montebrisas
> Apt. 2-203
> San Juan, PR 00926
>
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