As a member of
Family Nereididae, few if any segments are longer than wide, the notosetae
from the two sides do not almost meet along the dorsal midline, the prostomium
does not extend as a dorsal caruncle
back over the segments posterior to it, there is no circle of tentacles
around the mouth, the prostomium
has two antennae (photo), and a
pair of palps
which are differentiated into two units, the distal unit of which is
even though it is smaller than the proximal unit (photo).
Some of the setae
(visible when everted) is delineated into two parts, with a pair of
jaws on the distal part and conical teeth on both parts. The peristomium
has four pairs of tentacular cirri which arise on the anterolateral
(photo). Usually two
pairs of eyes are present.
the first two setigers
on all subsequent
Both the notopodia
and the neuropodia
which are often small, plus one to three conspicuous lobes above and
The shape and arrangement of the ligules
varies among species. In Nereis
vexillosa the ventral cirrus of all parapodia
is simple, the tentacular
cirri of the peristomium
are not constricted into several units (photo),
segment behind the peristomium
is not expanded into a large collar around the peristomium,
all of the paragnaths
on the eversible
are conical (not elongated transversely or comblike), some paragnaths
are present on the distal part of the proboscis,
the posterior notopodia
and the upper
ligule of the notopodia
in the posterior region is much larger than the lower ligule
and is strap-shaped, with a terminal cirrus (photo,
easily recognized characteristic). Color is greenish or
brown, often with blue tones; may appear iridescent in direct
Has 4 black eyes. The tentacular
cirri are short (photo).
The animal is often
large--up to 30 cm long and 1.2 cm wide.
vexillosa Grube, 1851
Common name(s): Banner sea-nymph, pile worm, sand worm, mussel worm,
vexillosa, about 24
cm long, found at Padilla Bay.
|(Photo by: Dave Cowles,
July 2009 )
How to Distinguish from
The large, strap-shaped upper ligule
in the posterior notopodia
is very helpful in identifying this species. In Nereis
grubei and N.
the upper ligule
is not strap-shaped. Nereis
has no paragnaths
on the distal proboscis. Nereis
brandti has no homogomphfalcigerous
on the posterior
Alaska to San Diego;
Pacific coast of Russia
Mid to low intertidal
Intertidal with mussels
and barnacles, on pilings, in sandy mud and cobbles, and in algal
The large jaws on the distal portion (maxillary ring) of the eversible
pharynx are used for seizing prey or tearing algae (Nereids usually eat
algae). The smaller denticles on the proximal portion (oral
are used for burrowing.
Family Nereididae are called sea nymphs and are common
in this area. Intertidal species are sometimes called
Nereids reproduce by releasing parts of their body as epitokes,
which swim to the surface in mating swarms. Nereid epitokes
are swollen with eggs or sperm, large parapodia,
paddle-like chaetae, and large eyes. Day length is important
lights can affect the timing of swarms. In our area, spawning
occur shortly before midnight. The mating swarms release
into the water which induces mating activity. The male epitokes
swarm first and the females will not release their eggs unless in the
of the males. The eggs are released into the water in the
through ruptures in the body walls. In N.
vexillosa the female releases an agglutinating material
her eggs. Both male and female epitokes
(heteronereids) die after spawning. The mass, with eggs
to the bottom and grows to about the size of a bluish-green chicken
Larvae remain as plankton for hours to months. In the Pacific
the mating swarms usually occur in late winter or spring.
This worm is often used for fishing bait. It squirms violently
jaws when captured, and may bite.
and Fairbanks, 1966
and Snook, 1955
and Hanby, 2005
O'Clair and O'Clair
et al., 1985
General Notes and
abundances, unusual behaviors:
(right) has two antennae and two large, two-segmented palps.
(segment behind the prostomium)
has 4 pairs of tentacular
cirri. This photo is a 3d composite made from a
series of photos
using a Keyence digital microscope. Photo by Dave Cowles,
This dorsal view of the posterior body shows the prominent, straplike
with attached terminal cirrus which are characteristic of this species.
This dorsal view of the parapodia
shows the small aciculae
with larger ventral and even larger dorsal lobes (ligules).
Most of the setae are compound (composed of more than one segment).
Closer examination by compound microscope would show this to be a homogomph
is a seta
in which the tip is comparatively blunt and curved. A homogomph
seta is a compound seta in which the basal segment ends in a slightly
capsule, the two sides of which are of approximately equal height (as
in which one side of the capsule is extended well out past the other).
Authors and Editors of Page:
Dave Cowles (2009): Created original page
CSS coding for page developed by Jonathan Cowles (2007)