Editing Shipworm (section)

== Anatomy ==
{{unreferenced section|date=April 2025}}
[[File:Taret Anatomie.JPG|thumb|300px|Disposition of the main organs in a shipworm. GDA: anterior digestive gland; GDV: ventral digestive gland, with its orifices in the stomach. Orifices uri. et gen., urinary and gential orifices. The left ventricle is sectioned near its base. The nerve ganglion is in blue. The distance between pallets and foot spans several time the animal's diameter.]]

Shipworm anatomy reveals the typical organs of a bivalve mollusk, although with dimensional or positional peculiarities due to the thinness and length of the occupied space. Furthermore, some structures find no equivalent in other bivalve groups.

* Gills are divided in two halves, the anterior one of small size, the posterior one much more developed. They are linked by the alimentary tract running on the side of the visceral mass.
* The heart-kidney system is tilted, bringing the kidneys in a dorsal position relative to the heart, whose atria find themselves behind the ventricle. Furthermore, the anterior and posterior aorta become respectively posterior and anterior.
* The anus opens at the end of a long anal tube.
* The digestive gland is divided into several parts, with separate orifices in the stomach.
* A vast [[caecum]] is linked to the stomach.
* The digestive tube bears a very peculiar structure, the gland of Deshayes, probably homologous to salivary glands,<ref name="Morton">{{cite journal |last=Morton |first=B. |year=1978 |title=Feeding and digestion in shipworms |journal=Oceanography and Marine Biology: An Annual Review |issue=16 |pages=107–144}}</ref> which link to the oesophagus and stretch to the dorsal side of the posterior part of the gills.
* The orifice of the gallery bears pallets with their own musculature.
* The siphon retractor muscles are inserted on the calcareous covering of the gallery, and not on the shell's valves which are much further out.
* The anterior and posterior anterior muscles have an antagonistic action.
Normally, the shipworm's body fills the entire length of the gallery, but the anterior region can retract itself slightly with respect to the latter's extremity. Without the gills, the viscera only cover one-fourth of the total length and only their anterior part is partially covered by the shell.<ref>{{cite journal |last=Sigerfoos |first=C. P. |year=1907 |title=Natural history, organization, and late development of the Teredindæ, or ship-worms |journal=Bulletin of the Bureau of Fisheries |id=Bureau of Fisheries Document No. 639 |volume=27 |pages=191–231}}</ref><ref name="Turner">{{cite book |last=Turner |first=Ruth |url=https://archive.org/details/surveyillustrate00turn/page/n7/mode/1up |title=A survey and illustrated catalogue of the Teredinae (Mollusca: Bivalvia) |publisher=The Museum of Comparative Zoology, Harvard University |year=1966 |location=Cambridge, Massachusetts |pages=8–45 |oclc=767789449}}</ref>