Flyachinskaya L.P., Lezin P.A. 2009. [Larval and juvenile shell development in the White Sea bivalve Hiatella arctica (Linnaeus, 1767)] // Invertebrate Zoology. Vol.5 (for 2008). No.1: 39–46 [in Russian, with English summary].
White Sea Biological Station, Zoological Institute RAS, Universitetskaya nab. 1, St. Petersburg, 199034, Russia. E-mail: email@example.com
KEY WORDS: Hiatella arctica, veliger, pediveliger, hinge development.
ABSTRACT: Larval and juvenile shell development in the White Sea bivalve mollusk Hiatella arctica L. was studied using light microscopy and computerized 3D-reconstruction. The veliger and the pediveliger larvae of Hiatella are easily recognizable in plankton samples because of the triangular shape of the shell. The larvae of H. arctica differ from the other Hiatella species by the more pronounced triangular shape. After metamorphosis, two or more posterior dorsal spines appear on dissoconch shell. These spines are well pronounced in juvenile stages of H. arctica, but disappear in adults. In H. arctica, provinculum on the early stages is a simple plate on the dorsal side of a shell. The hinge of pediveliger forms independently of provinculum. A rectangular flat tooth shifted to the anterior end of shell forms on the right valve. A similar tooth shifted to the posterior end of shell develops on the left valve. The lateral hinge protuberance forms behind the central depression of the shell. At first, the primary internal ligament forms posteriorly, then it moves to the middle of the shell. The results of present investigation support the opinion stated by Malakhov and Medvedeva (1993) that the heterodont hinge teeth form de novo (independently of provinculum) and that the heterodont hinge replaces provinculum in the evolution of bivalve mollusk shell development.