DIOSACCUS SP. AFF. DENTATUS (THOMPSON ET A. SCOTT) (COPEPODA, HARPACTICOIDA) FROM MACTAN ISL., THE PHILIPPINES

Abstract

During a short stay in the Philippines in 1979, I obtained some samples of marine and brackish-water meiobenthos. Although the examination of these samples is in process, it has been revealed that one of the samples, which was collected for a study of marine epiphytic animals, was extremely rich in harpacticoid copepods. Among them, I have found an unfamiliar harpacticoid female of the genus Diosaccus Boeck (Diosaccidae), whose body shape, especially its impressive appearance of thorax with dorsolateral protuberances, has strongly attracted my attention. Within the genus, such a prominent characteristic is known only for D. dentatus (Thompson et A. Scott, 1903) Lang, 1965, which was originally described from Ceylon under the name Dactylophusia dentata based upon a material obtained from washings of pearl oysters and is unique within the genus in having "dents" on the thorax. The present specimen, however, differs from the original description of D. dentatus in some other characters. The specimen is fully described in the present paper and compared with the description of D. dentatus. Before going further, I would like to express my sincere gratitude to Professor Mayumi Yamada of Hokkaido University for reading the manuscript.