REPRODUCTION AND DEVELOPMENT IN A PUGET SOUND SPECIES OF NOTOMASTUS (POLYCHAETA, CAPITELLIDAE)
Schroeder, P. C.
Dept. of Zoology, Washington State University Pullman, WA 99194-4236, USA
Notomastus sp. is an abundant infaunal polychaete in brackish, anaerobic mud in upper Henderson Inlet, south Puget Sound, Washington State, USA. Attempts to identify the species have revealed inconsistencies between types and typical specimens (L. Harris, unpublished). Some 17 collections were made between March, 1994 and August, 1996. Examination of samples of coelomic fluid from 5-10 individuals per collection revealed that gametogenesis extends from April to early August; mature gametes disappear in late July or early August.. Mature oocytes ranged from 65-80 æm. Artificial fertilization of coelomic gametes at the end of July produced feeding trochophores which developed slowly at 18§C. and did not settle for at least 8 weeks, when as many as 6 larval segments were present. Hooded hooks and capillary setae develop in separate larval segments. Settling requirements remain unknown. Notomastus larvae were not detected in plankton above the benthic population. Oocyte diameter and trochophore morphology differ from those reported for the European N. latericeus, which produces 150 æm oocytes.