286 SEALE. 



DISTRIBUTION, HABITS, GROWTH, AND PRODUCTION OF PHILIPPINE TREPANG. 



The wide distribution of these apparentlj^ helpless, sedentary sea- 

 animals is a matter of interest and astonishment to all who give the 

 subject any thought. ■ Twenty of the species found in the Philippines are 

 also common to Polynesia, 16 to the Malay Archipelago, 30 to the Red 

 Sea and the coast of Africa, while 3 extend even to the west coast of 

 America. The majority of the recorded forms are believed to be well 

 distributed throughout the PhiUpjDines, but are most abundant in the 

 Sulu Archipelago. The supply for Manila comes chiefly from Tacloban, 

 Polillo, and Ambos Camarines. They are found in water of various 

 depths, even in very shallow water and also on reefs dry at high tide, 

 down to 137 fathoms and even to much greater depth. Sheltered places- 

 inside the coral reefs where the bottom is of coral sand seem to be favorite 

 haunts of the bark sim and hong che forms, while moi whar che, gan 

 sim, and oe seem to prefer water of gTeater depth just at the- edge of 

 the reef. The greater number of the trepang appear to pass large quan- 

 tities of sand and mud through their alimentary canals ; from this sand 

 they extract the small animals and plants on which they feed. On 

 Arboles Eeef, Gulf of Davao, Mindanao, I once noticed a large number 

 of Colochirus quadrangulus Less, feeding on sea-weed which at low tide 

 was about 75 millimeters (3 inches) under water. They were so abun- 

 dant that it was scarcely possible to step without treading them down, 

 and in one scoop of an ordinary dip net I secured 57 of them. It is 

 probable that during the season for depositing the eggs they all seek 

 the reefs or rocky crevices. Mitsukuri,* in his most interesting paper 

 on the common Japanese trepang, ^vrites, referring to the Island of Oki, 



The people there have for a hundred years or more been in the habit of putting 

 up loose stone-piles in the shallow sea in order to obtain a supply of this trepang. 



Nowhere in the Philippines is this devise put into practice although it 

 doubtless would yield profitable results. 



Practically nothing is kno-wn about the breeding time of the Philip- 

 pine trepang and it is a subject well worth investigating. In Japan (as 

 abstracted from the above paper), the trepang spawn in May and June, 

 and at the end of the first year have a maximum size of 5 by 35 centi- 

 meters. They reach the adult condition at the end of the second year, 

 but do not spawn until the end of the third; some individuals probably 

 live two or three years after spawning. The young specimens are white 

 and transparent, and they attach themselves to the roots of algse, or seek 

 rocky crevices in sheltered localities. Hence a rock pile affords a 

 natural collecting ground for the very young as well as for the old. 

 Japan has put some measures in force setting aside certain localities as 



* Notes on the Habits and Life-History of Stichopus japonicus Selenka. Annot. 

 Zool. Jap. (1903-06), 5, 1-21. 



