''Saccoglossus bromophenolosus'' is a species of
acorn worm (class Enteropneusta) occurring in the northwestern Atlantic Ocean and the northeastern Pacific Ocean. It grows to a length of about and lives in a burrow in soft sediment in the intertidal and subtidal zones. The scientific name refers to
2,4-dibromophenol
2,4-Dibromophenol is a brominated derivative of phenol with the molecular formula C6H4Br2O. It belongs to the bromobenzenes, which are organic compounds containing bromine atoms attached to a benzene ring.
Properties
At room temperature, 2,4-dib ...
, a secondary metabolite present in this worm.
[
]
Description
Like other acorn worms, this soft cylindrical worm is divided into three parts, the proboscis, the collar and the trunk. The proboscis is long and slender with a groove along the top. The mouth is located on the underside where it joins the thick, fleshy collar. A fold at the back of the collar overhangs the trunk, and the anus is at the tip of the trunk. The total length is up to , the proboscis is white to beige, the collar is orange, red or reddish-green and the trunk is either brownish-green or rather pale.
Distribution and habitat
The species is native to the northwestern Atlantic Ocean where its range extends from Maine to Nova Scotia. It is also present in the northeastern Pacific Ocean, in Padilla Bay and Willapa Bay
Willapa Bay () is a bay located on the southwest Pacific coast of Washington state in the United States. The Long Beach Peninsula separates Willapa Bay from the greater expanse of the Pacific Ocean. With over of surface area Willapa Bay is the ...
in Washington state, where it is thought to have been introduced with a consignment of oysters from the east coast. It is typically found burrowing in mud, mostly in the intertidal zone
The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...
, but also subtidally down to about .[
]
Biology
''S. bromophenolosus'' moves through the sediment by thrusting its proboscis forward and then contracting it longitudinally to form a swelling. This bulge is then worked backwards along the proboscis, which pulls the worm forwards. The collar and trunk follow passively. The beating of cilia
The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...
also helps move sand and silt. Food particles are trapped in mucus and moved to the mouth by ciliary action, and the worm also swallows a lot of sediment and presumably obtains some nourishment from detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commun ...
. The sexes are separate. Fertilisation takes place in the water column. The eggs are yolky and large and development is direct, without a mobile larval stage.[
The worm contains high concentrations of 2,4-dibromophenol in its tissues. It is unclear what function this serves, but it may deter ]predators
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
or convey some measure of resistance to microorganisms.
References
{{Taxonbar, from=Q2403371
Enteropneusta
Animals described in 1994