ALIEN LIFE FORMS? NO, JUST BRYOZOANS
Probably the strangest creature in the Connecticut River is
Pectinatella magnifica "The Blob."
For inquiries contact Doug
This organism is not from outer space, nor is it the result
of mutations caused by radioactivity from nuclear power plants;
Pectinatella magnifica is a member of the animal phylum
Ectoprocta (common names: bryozoans, moss animals), a group with
a fossil record extending back to the upper Cambrian
(500,000,000 years ago!).
The majority of bryozoans are marine (several thousand
species), but one class, the Phylactolaemata, is found
exclusively in fresh water. Three species of this class have
been found by divers in the Connecticut River.
The basic ground plan of a bryozoan superficially appears
to have more in common with a coral; they are, in fact,
ecological analogs. Bryozoans and
corals are in different phyla and are unrelated. What seems
to be an individual is actually a colony of zooids (not polyps as
in corals). Each zooid has whorls of delicate feeding tentacles
swaying slowly in the water catching food.
The following anatomical description is from Wood (1989):
Lophophore: a food-gathering structure bearing many ciliated
tentacles which may be either extended flower-like during
feeding, or collapsed and completely withdrawn into the interior
of the colony.
Mouth: situated centrally at the base of the tentacles;
phylactolaemates have a special lobe (epistome) which hangs over
the mouth and which is believed to have an important sensory
Gut: the most prominent feature is a long caecum in which
ingested particles are mixed thoroughly with vigorous peristaltic
Funiculus: a thin cord of tissue loosely joining the end of the
gut to the colony wall. The funiculus is the site of statoblast
production and spermatogenesis.
Central Nerve Ganglion: inconspicuously located between the mouth
and the anus, with a major nerve tract extending into each arm of
Cystid: this is the laminated living and nonliving structure that
separates the coelom from the external environment. Its
outermost layer (ectocyst) consists of secreted material, which
is some species is a slimy mucus, while in others it is a
chitinous, somewhat leathery cuticle.
Connecticut River Bryozoans:
The colony is gelatinous, firm and slimy to the touch. The
inner gelatinous mass is 99% water. The surface appears divided
into rosettes, each with 12-18 zooids. Massive colonies may
exceed 2 feet (60 cm) in diameter, although more typical sizes
are 1 foot or less. The colonies form on submerged logs, twigs,
even wooden docks.
Colonies are clear, gelatinous and without lobes or branches.
Underwater they are white and typically 2-3 inches long and 1
inch wide. They sometimes resemble giant fuzzy caterpillars.
C. mucedo colonies occur on aquatic vegetation as well as
the undersides of rocks in deeper waters.
This species is
state-listed as a rare species, although a new population has
been discovered growing in a deep abyss
in the river. The colony size of L. carteri is small and
unbranched, with a soft, transparent body wall that allows a
clear view of the internal structures. Colonies typically have
fewer than 20 zooids and are less than 6 mm (1/4 inch) in
diameter. The colonies are toxic to fish, a poisonous substance
apparently is released when colonies are damaged.
Wood, T. S. 1989. Ectoproct bryozoans of Ohio. Ohio Biol.
Surv. Bull. New Series, Vol. 8, no. 2.
Smith, D. G. 1985. Lophopodella carteri (Hyatt),
Pottsiella erecta (Potts), and other freshwater
ectoprocta in the Connecticut River (New England,
Ohio J. Sci 85:67-70.
Smith, D. G. 1992. A new freshwater moss animal in the genus
Phylactolaemata:Plumatellidae) from New England (U.S.A.).
Can J. Zool. 70:2192-2201.