Search results
Results From The WOW.Com Content Network
The pallial line is a mark (a line) on the interior of each valve of the shell of a bivalve mollusk. This line shows where all of the mantle muscles were attached in life. In clams with two adductor muscles the pallial line usually joins the marks known as adductor muscle scars, which are where the adductor muscles attach.
A hinge line is an imaginary longitudinal line along the dorsal edge of the shell of a bivalve mollusk where the two valves hinge or articulate. The hinge line can easily be perceived in these images of a mussel shell and an ark shell. [1] [2] [3]
The existence of this pocket shows even in an empty shell, as a visible indentation in the pallial line, a line which runs along parallel to the ventral margin of the shell. [10] The bivalve's two siphons are situated at the posterior edge of the mantle cavity. [11] There is an inhalant or incurrent siphon, and an exhalant or excurrent siphon. [12]
The pallial sinus is an indentation or inward bending in the pallial line on the interior of a bivalve mollusk shell's valves that corresponds to the position of the siphons in those types of clams which have siphons (i.e. siphonate). The position of the pallial sinus is often clearly visible as a shiny line on the inside of the bivalve shell ...
A bivalve shell is the enveloping exoskeleton or shell of a bivalve mollusc, composed of two hinged halves or valves. The two half-shells, called the "right valve" and "left valve", are joined by a ligament and usually articulate with one another using structures known as "teeth" which are situated along the hinge line.
Hinge teeth are part of the anatomical structure of the inner surface of a bivalve shell, i.e. the shell of a bivalve mollusk. Bivalves by definition have two valves, which are joined together by a strong and flexible ligament situated on the hinge line at the dorsal edge of the shell. In life, the shell needs to be able to open slightly to ...
The mystery mollusks are hermaphrodites, which include both male and female reproductive organs. When it is time to release eggs, they descend and use their foot to temporarily attach to the seafloor.
In a few cases, the trochophore remains within the egg (and is then called lecithotrophic – deriving nutrition from yolk), which hatches to produce a miniature adult. Unlike most other molluscs, there is no intermediate stage, or veliger, between the trochophore and the adult. Instead, a segmented shell gland forms on one side of the larva ...