EQUIPMENT 



For excursions from the habitat we used SCUBA (double tanks) and the 

 GE Mark 10 rebreather units as breathing devices. General equipment 

 consisted of underwater lights, plastic slates and clip boards upon 

 which to record our observations, pencils, and nylon mesh bags for 

 holding live specimens. Ten percent formalin seawater and mercuric 

 chloride in plastic squeeze bottles were used to drive reluctant 

 octopods from dens or hiding places. Octopods were narcotized with 

 3% urethane- seawater in the habitat. Glass slides, coverslips, and 

 light microscopes in the habitat were used for parasite diagnoses. 

 Trypan blue was used to mark (tag) individual octopods. 



PROCEDURES 



Octopods. 



Animals when encountered were recorded; their location, relative sizes, 

 and behavior noted. A total of 30 individuals were sighted and of 

 these, 10 were captured and brought to the habitat for examination 

 (Table I) , Once narcotized with urethane they could be handled easily 

 for identification (we used the Key to Octopod Species of the Western 

 Tropical Atlantic by Voss, 1966). The mantle ligament (Adductor muscle) 

 was cut, the mantle folded back, and the individual was sexed, aged, 

 and examined for parasites. To determine if dicyemid mesozoans (unique 

 octopod parasites) were present, a sample of urine was removed from the 

 renal sacs by pipette and examined under the microscope. Another sample 

 was taken from the rectum and a visual examination was made of the viscera 

 and gills for macro-parasites. Subcutaneous injections of trypan blue 

 in varied patterns on the dorsal mantle and arms allowed for subsequent 

 recognition of specific individuals (Fig. 1). Before being returned to 

 the site of capture for release, the animals were placed for recovery 

 (30 to 45 minutes) in a mesh bag suspended in the trunk. 



Squid. 



Incidental observations of behavior were made when squid were encountered. 

 No attempt was made to capture, examine, or mark individuals. 



RESULTS 



Octopods : 



Three, possibly four, species of Octopus were observed (See Table I for 

 general summary of observations on three identified species). The re- 

 sults of observations on each of the three species are given separately. 



VI-222 



