Species Corbicula Research Articles

Novel reproductive modes in freshwater clams: brooding and larval morphology in Southeast Asian taxa of Corbicula (Mollusca, Bivalvia, Corbiculidae)

AbstractWhile the majority of marine bivalves are oviparous, the two freshwater families among the order Veneroida, i.e. Corbiculidae and Sphaeriidae, comprise species with ovoviviparous and viviparous reproduction. Within the Corbiculidae, the genus Corbicula, which is well‐known for its invasive and, thus, ecologically important representatives, is characterized by (i) a wide range of limnic habitats, inhabiting both brackish water and freshwater environments, and (ii) contrasting modes of reproduction, including ‘planktonic’ development via a free‐swimming larva vs. intrabranchial incubation (brooding) of shelled juveniles. The present investigation of five species of Corbicula from the Indonesian islands Sumatra and Sulawesi, which were hitherto not studied anatomically, adds to the diversity in reproductive patterns in this genus. As a unique feature among Corbicula we here report on two newly observed modes of brooding in species endemic to Sulawesi, (i) tetragenous brooding (i.e. in both demibranchs) in Corbicula possoensis Sarasin & Sarasin, 1898 from Lake Poso, and (ii) prolonged incubation in the maternal gills, with juvenile shells reaching up to 1.3 mm in length and with a well‐developed hinge in C. linduensis Bollinger, 1914 from the Lindu River system. In contrast, a third method is seen in the following taxa that incubate their young in their inner demibranchs only until the stage of juveniles with straight‐hinged shells (D‐shaped): C. matannensis Sarasin & Sarasin, 1898 from Lake Matano and Lake Mahalona, C. loehensis Kruimel, 1913 from Lake Masapi (all on Sulawesi) and C. moltkiana Prime, 1878 from Lakes Maninjau and Singkarak (on Sumatra). Details of the anatomical and histological features of ctenidia are described for each type of brooding, and some trends in the evolution of reproductive strategies within the Corbiculidae are discussed, comparing them with those known from other limnic molluscs.

Differences in Inhalant Siphonal Papillae among the Japanese Species of Corbicula (Mollusca : Bivalvia)

Differences in Inhalant Siphonal Papillae among the Japanese Species of Corbicula (Mollusca : Bivalvia)

On the Corbicula (or Cyrena) Fluminalis geologically considered

Mr. Jeffreys having stated that he had identified the species of Corbicula found by Mr. Prestwich in a raised sea-beach at Kelsey Hill, in Yorkshire, with that of the Grays deposit, as well as with the recent species from the Euphrates and the Mle, proceeded to give a sketch of the history and synonymy of the species under consideration; and he added some remarks which follow. In 1774, O. F. Müller (the celebrated Danish naturalist) described, in his ‘Term. Terr, et Fluv. Hist.’ p. 205, a shell from the River Euphrates, under the name of Tellina fluminalis . His description exactly corresponds with the triangular form of the fossil shells from Kelsey Hill and Grays. In 1811, Megerle v. Mühlfeldt founded on this and other allied species the genus Corbicula ; which name is now adopted by conchologists. In 1818, Lamarck proposed for the same species the generic name of Cyrena ; apparently not being aware of Mühlfeldt's publication. Many recent species of Corbicula (or Cyrena ) have been described by Lamarck, Férussac, and others. The most westerly station given by any of the conchologists is the Nile. Goldfuss, Nyst, Galeotti, Philippi, Searles Wood, and others have also described many Tertiary species of Corbicula (or Cyrena ) under other names. The most easterly locality given by any of the palæontologists is Cefali, near Catania. It is, however, highly probable that most of these species, whether recent or fossil, ought to be united.