黄海多毛类裂虫科小型种的初步研究

1987～1991年在黄海进行小型多毛类调查时,采到的裂虫科小型种标本,经鉴定有18种,其中9种在我国是首次记录。     

Haplosyllis spongicola Grube Polychaeta, Syllidae Associated with Two Species of Sponges from East Africa Tanzania, Indian Ocean

Abstract. The presence of Haplosyllis spongicola G rube 1855 Polychaeta, Syllidae in two sponge species from the Indian Ocean Tanzania, Theonella swinhoei G ray 1868 and Liosina paradoxa THIELE 1899, was detected. Polychaetes lived exclusively inside the aquiferous system of the sponges, reaching a mean density of 68 individuals · cm^-3 in T. swinhoei and 148 individuals · cm^-3 in L. paradoxa Acetone extractions were prepared from sponge tissues of T. swinhoei and L. paradoxa and from the gut contents of their respective inhabiting polychaetes. Absorption spectra matched for each sponge/polychaete pair. These data confirm that polychaetes exploit the soft parts of the sponges in which they live. In addition, in L. paradoxa direct confirmation of a predatory activity of worms on sponge internal tissues was obtained on the basis of the finding of terrigenous sediments, which typically reinforced the sponge canal walls, in the gut lumen of the inhabiting polychaete. No evident ultrastructural changes of the host tissue due to endobionts have been observed. These results confirm the parasitic/micropredatory habits of H. spongicola. Data on different morphological characteristics of H. spongicola living in the two sponge species are presented and discussed.     

Annual Variation of the Reproductive Activity of Three Exogoninae Species (Polychaeta: Syllidae) from the Western Mediterranean

Abstract.  During a 12-month period (from May 2000 to the end of April 2001), the reproductive activity of three Exogoninae species was studied: Grubeosyllis clavata (Claparède, 1868), G. vieitezi (San Martín, 1984) and Sphaerosyllis (Sphaerosyllis) hystrix Claparède, 1863. A sample consisting of two replicates was collected every second month, and the individuals of each species were counted and assigned to different reproductive categories (immature, mature, and bearing eggs or embryos). The populations of the three species showed a dramatic decline in numbers during summer 2000. In regard to the reproductive activity, the two species of Grubeosyllis showed a continuous activity during the whole year, with a peak in July for G. vieitezi and in September and November for G. clavata . In contrast, S. (S.) hystrix had a pause in its reproductive activity in late summer when no mature or offspring-carrying specimens were found. A relationship between the reproductive cycle and the brooding type (dorsal eggs versus ventral embryos) is likely, although further studies on other exogonin species are necessary to confirm the hypothesis suggested by the present results.     

Victims of Avicularia

Abstract. .The function of the sessile "trap-door" avicularia of cheilostome bryozoans has been the subject of much speculation but relatively little observation. During studies of reef dwelling cheilostomes, avicularia of this type were seen to capture syllid polychaetes. This diverse group of small predatory worms, commonly found in the same habitats as bryozoan colonies, may be important factors in bryozoan ecology and evolution.