monitoring the fecudity of S. partitus

William Figueira wff at
Wed Apr 26 13:48:36 EDT 2000

I wish to estimate the total number of eggs received by an individual 
male bicolor damselfish (S. partitus) during a reproductive period.  I am 
considering using the same technique used by Knapp who worked with the 
same species, or Itzkowitz who worked with a very similar damselfish (S. 
leucostictus).  Both techniques involve setting out an artificial nesting 
site for the male and then monitoring the amount of eggs received on that 
nest site by tracing the perimeter of individual clutches onto acetate 
sheets using a wax pen.  The difference between the two techniques is 
chiefly that Knapp used 13 cm diameter clay flower pots and Itzkowitz 
used 4, 10 cm long by 7.5 cm diameter PVC pipes laid out in a cross 
pattern as the artificial nest.

My questions are:

1. Do the damselfish lay eggs on the inside or outside of the nest 
structure?  I would guess inside however, if that is the case, how does 
one manage to trace the outline of clutches in such confined spaces?

2. Does anybody have any other related or completely different techniques 
that might work for this species?  I have wondered if using some sort of 
clear plastic insert into the nests would be possible.  That way, 
assuming that eggs are laid on the inside of the nest, it could be 
removed and clutch outlines could be traced from the outside.

Any and all information is much appreciated.  Thanks for your attention.


  Will Figueira			email: wff at   
  Duke University Marine Lab		phone: (252)504-7572
  135 Duke Marine Lab Rd		fax  : (252)504-7648
  Beaufort, NC 28516  USA

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