The Eyes and the Photonegative Behaviour of Nephtys (annelida, Polychaeta)

The Possible Role of the Supra - Oesophageal Ganglion in the Responses of Nephtys ( Polychaeta , Annelida ) to Changes in Hydrostatic Pressure

INTRODUCTION The periodic swimming behaviour shown by the burrowing polychaete Nephtys, when denied access to sand, is readily modified by changes in hydrostatic pressure. An increase in pressure stimulates the worm to swim, while a decrease in pressure inhibits swimming, and some of the parameters of these responses have been described previously (Morgan, 1969). However, nothing is known of th...

The responses of Nephtys (polychaeta: Annelida) to changes in hydrostatic pressure.

In recent years it has become evident that many marine invertebrates are sensitive to changes in hydrostatic pressure, and the subject has recently been reviewed by Knight-Jones & Morgan (1966). Most are planktonic forms, and their responses appear to be of a depth-regulatory nature (Baylor & Smith, 1957; Moore & Corwin, 1956). However, a few normally benthic types have also been shown to be pr...

Identification key to Nephtyidae (Annelida) of the Sea of Okhotsk

Currently, 15 species of Nephtyidae (Annelida) are known from the Sea of Okhotsk (north-western Pacific). A new user-friendly identification key is presented with a brief description for each species. The taxonomic positions of three closely related species, Nephtys brachycephala Moore, 1903, N. schmitti Hartman, 1938 and N. paradoxa Malm, 1874, are revised. The distributions of two species, Ne...

Feeding Ecology of Nereis diversicolor (O.F. Müller) (Annelida, Polychaeta) on Estuarine and Lagoon Environments in the Southwest Coast of Portugal

The feeding ecology of Nereis diversicolor (O. F. Müller, 1776) (Annelida: Polychaeta) was studied over 14 months at three estuarine-lagoon systems of the Southwest coast of Portugal (Odeceixe, Aljezur and Carrapateira). The analyses of digestive tract revealed that diet change according to site, period of the year and individual sizes. There are no differences in the digestive contents between...

The Blood - system in the Serpulimorpha ( Annelida , Polychaeta )