14 



OKHAMANDAL MARINE ZOOLOGY REPORT 



of loose blocks of iload ooral am present along tin; sontliern portion of Borio and 

 these give sheltci' to nnmliers of crabs, small fishes, and crusting sponges. Large 

 zoa,nthids were nut uneoramon associated witli large fleshy alcyonarians [Sareopliyton). 



The formation of Manguuda reef was found very mucli like that of Borio, 

 rich locally in corals, anemones, oeto])ns, a.nd, at extreme low water, fine colonies 

 of a caulitlowerdike pale orange DtnKlroru'phtliya [D. hreviraiaa). 



On the higher level in the cimtre of the re(.-f, the small coral fragments 

 forming the surface are infested with Vermetus tubes and witli multitudes of 

 brood edible oysters {Ostrea) whose sharp edges make walking barefoot most 

 dangerous. 



In the shallows towards Borio, a profusion of red alga3 of several species 



was present. 



Fig. 4. — Inner and outer view of the valves of a Pearl Oyster (J/, rti/i/arif:) 

 from th(> Gulf of Kutch. 



It was on Mangunda that we at last found the pearl oyster alive — a single 

 individual at extreme low water attached to the overhanoino- side of a l*oulder. 

 It was about eighteen months old, very fat and in an excellent condition of health. 

 Besides this not less than ten dead shells were found of an age, when living, 

 of from one and a half to five years. All were of the Ceylon species, and as the 

 other live and dead oysters found at Pagar Kada and Adatra were similar, it would 

 seem that the Kutch pearl oysters all belong to M. vulgaris. 



On another day a visit was paid to Pagax Kada, a reef of much greater size 

 than either Borio or Mangunda. In many respects it is a reef of special interest 

 for the reason that on account of its large area some parts of the central region 

 have peculiar pliysical characteristics. These, however, need not be particularised 

 here, as our examination of this reef confirmed the conclusion come to from a 

 study of Borio and Mangunda, that the hahitat (_)f pearl oysters in these waters 



