The embryology of the echiuroid
worm, Urechis caupo.
A redescription of Nemertoscolex parasiticus Greeff, 1879, an apparently endoparasitic heteronemertean from the coelomic fluid of the echiuroid
Echiurus echiurus (Pallas).
Actions of noradrenaline and some other biogenic amines on the body-wall muscles of an echiuroid
, Urechis unicinctus.
CB impact on fertilization is limited to the first 6 mm PI in several urchin species (Longo, 1980; Byrd and Perry, 1980; Schatten and Schatten, 1980), and echiuroid
worms (Gould-Somero et al.
This phenomenon is also characteristic of sperm of the echiuroid Urechis caupo, in which CK activity approaches 10 [[micro]moles] * [min.
The above pattern, as seen in major protostome (polychaetes, echiuroids, and sipunculids) and deuterostome (echinoderms, tunicates) groups, indicates that when an organism has the potential to express more than one phosphagen type, if CP/CK is one of the possibilities, it is the type that will, without exception, be expressed in spermatozoa.
The fast electrical polyspermy block has been further observed in many animal species, such as starfish (Miyazaki and Hirai, 1979), the echiuroid Urechis (Gould-Somero et al.
In the brown alga Fucus (Brawley, 1991) and in marine invertebrates such as the sea urchin, the starfish, the echiuroid Urechis, and the nemertean Cerebratulus (Jaffe, 1976, 1980; Miyazaki and Hirai, 1979; Gould-Somero et al.
This study shows that eelpouts, Tanner crabs, crangonids, hermit crabs, polychaetes, and echiuroids
were the principal prey of Pacific cod collected in Pavlof Bay in 1995.