Marking Spiny Lobsters, Panulirus argus , and Blue Crabs, 

 Callinectes sapidus . With Biological Stains 



Thomas J. Costello, Donald M. Allen, and Carl H. Saloman 



Biological stains injected into penaeid shrimp produce a lasting 

 mark and have been used extensively in mark-recapture experiments. Suc- 

 cess of the stain injection method suggested that such a procedure could be 

 used to mark other decapods. Since the spiny lobster (Panulirus argus) and 

 the blue crab ( Callinectes sapidus ) have commercial importance and are 

 available in south Florida waters, these two species were selected to test 

 their acceptance and retention of biological stains. 



The injection equipment consisted of j-cc. tuberculin syringes 

 with 27-gauge, ^-inch hypodermic needles. A larger syringe, perhaps 2 cc. , 

 would be preferable for extensive field use. Two stains were used, one a 

 0. 25-percent aqueous solution of Trypan blue, the other a 0. 5-percent solu- 

 tion of fast green FCF. 



The spiny lobster has a physical structure comparable to that of a 



penaeid shrimp; therefore, the quan- 

 tity of stain per g. used for shrimp 

 weighing about 30 g. was multiplied 

 proportionately to mark the lobsters, 

 which weighed roughly 180 g. each. 



Injection was made laterally 

 into the abdomen at the articulation of 

 the fourth and fifth segments, where 

 the needle was inserted its full length 

 at an angle of about 45 degrees. Al- 

 nnost immediately after injection, the 

 lobsters acquired a general faint bluish 

 or greenish tinge, depending upon the 

 stain used, which could be seen through 

 the more transparent portions of the exo- 

 skeleton. However, all color which 

 could be seen externally disappeared 

 within 2 days. After 40 days, the agile 

 and healthy -appearing survivors were 

 killed. The gill filaments of all the 

 lobsters were clearly marked with 

 either green or blue. Molting in one 

 individual did not affect stain retention. 

 The concentration and volume of stain 

 injected seem adequate to mark spiny 

 lobsters of the size used. 



INJECTION SITE 



Points for injecting marking stains 

 into spiny lobsters and blue crabs. 



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