On July 6, I began saturation diving from the TEKTITE habitat and 

 during the two weeks that followed used scuba for about 40 hours 

 and a rebreather for 46 hours in depths of 10 to 24 m. 



Using a plastic slate for notes, I recorded distribution of plants 

 and plant-eating fishes, and observed individual fishes, as well as 

 the activities of groups of mixed species that foraged together 

 during the day. Fishes near the TEKTITE habitat were offered samples 

 of various plants from the plain and the responses were recorded. 



Selected samples of plants were collected and sent to the surface 

 for preservation and later critical examination. Voucher herbarium 

 specimens were prepared of all plants species recorded, and these 

 will be deposited at the U.S. National Herbarium, Washington, D. C. 



A single Eupomocentrus partitus was collected to document the study 

 on this small damselfish. The specimen will be deposited at the 

 Los Angeles County Museum of Natural History. 



RESULTS 



Reef Vegetation 



On the reef proper in 3 to 20 m depth, few plants are evident. 

 In crevices, the spherical green algae, Valonia vent ri cos a is common, 

 and a turf of fine filamentous blue-green, green, red and brown 

 algae and diatoms occurs on some rocks, hard coral and artificial 

 substrates, including the habitat itself. (Fig. 4). 



Brown algae (Phaeophyta) predominate in this area. Species of the 

 microscopic filamentotis genera Ectocarpus , Giff ordia , Sphacelaria , 

 Myrionema , and the decumbent Dictyota bartayresii and Lobophora 

 variegata grow on hard surfaces, especially the bases of stony corals. 

 A few small plants of Padina sanctae-crucis occur in protected places. 

 Red algae (Ehodophyta) on the reef include the filamentous Gonlotrichum 

 alsidii, and Acrochaetium spp., several species of Ceramium , the small 

 stiff Gelidium corneimi , occasional Laurencia plants, and several 

 encrusting and corraline species . Certain green algae (Chlorophyta) 

 occur within the living stony corals, and are probably utilized for 

 food by fishes that scrape and bite pieces of coral. But green algae 

 other than the endozoic forms include only Valonia spp . , Neomeris 

 annulata, a few sprigs of Cladophora , the minute epiphyte Diplochaete 

 solitaris , well-protected Bryopsis pennata plants, and in occasional 

 open sandy places within the main reef, patches of Udotea verticillosa 

 and U. conglutinata . 



VI-135 



