Description:
Like all ctenophores,
this species swims by means of 8 ciliated (ctene)
rows which meet at the aboral
side and run down the sides of the body. This ctenophore is a
lobate
ctenophore, meaning that it has two large lobes at its oral end (to the
right in the photo above). It has small tentacles of 2
different
kinds near the mouth, between the lobes. One type of tentacle
is
branched and arises from sheaths near the mouth. The other
type is
small but abundant, in tracts leading to the mouth. The body
surface
of this species is smooth and colorless except for rows of dark spots
which
continue along the body in the same line as the ctene rows (photo, photo). The ctene
rows are not all the same length, and run only 1/2 to 2/3 the length of
the body. In large individuals these spots may be coalesced
into
lines. Length to 15 cm, usually smaller.
How to Distinguish from Similar Species: This is one of the few lobate ctenophores in our waters. Several similar species are highly flattened, but this species is not flattened. Others may be able to clap their lobes together in a "frog kick" for escape swimming, but this species cannot. Geographical Range: Atlantic temperate to arctic, Pacific southern CA to Arctic, Arctic oceans. This is the most common lobate ctenophore along our Pacific coast. Depth Range: Surface to 1000 m (largest individuals live deeper) Habitat: Pelagic Biology/Natural
History:
This species mostly cruises vertically, upward or downward.
One of
the individuals we captured had recently swallowed a copepod.
May
be eaten by Beroe
ctenophores.
This ctenophore is luminescent.
References:Dichotomous Keys:Carlton, 2007 Flora and Fairbanks, 1966 (as B. microptera) Kozloff, 1987, 1996 General References:
Scientific Articles: Web sites: General Notes and
Observations: Locations,
abundances, unusual behaviors:
In this view the dark spots which are in rows along the lobes in line with the ctene rows can be clearly seen. Authors and Editors of Page: Dave Cowles (2009): Created original page CSS coding for page developed by Jonathan Cowles (2007) |