scholarly journals Larval Shell Muscles in the Abalone Haliotis kamtschatkana

1997 ◽  
Vol 193 (1) ◽  
pp. 30-46 ◽  
Author(s):  
L. R. Page
Keyword(s):  
Larval Shell ◽  
Shell Muscles

Larval and juvenile development of the Iceland cockle Ciliatocardium ciliatum (Fabricius, 1780) (Bivalvia: Cardiidae)

2020 ◽  
Vol 324 (2) ◽  
pp. 242-251
Author(s):  
L.P. Flyachinskaya ◽  
P.A. Lezin
Keyword(s):  
Lateral Position ◽  
Larval Shell ◽  
Subtidal Zone ◽  
Larval Stages ◽  
Posterior Shoulder ◽  
Blade Shape ◽  
The Right ◽  
Lateral Structures ◽  
Juvenile Development ◽  
Concentric Structure

The paper considers the development of Ciliatocardium ciliatum from the stage of straight hinge to juvenile. In the White Sea the spawning of C. ciliatum begins at the end of June, larvae at different stages of development occur in plankton until the end of September. The earliest of the larvae found had shell lengths of 123–130 µm. The paper first examined the anatomy and structure of the larval shell of C. ciliatum. During the development, the main stages of organogenesis were described and special attention was paid to the formation of the digestive and muscular systems. The digestive system begins to function when the larva reaches a size of 170–180 µm. The digestive gland has a two-blade shape and is shifted to the right side. The foot is formed at a size of 230 µm, the gill rudiments appear when the larva reaches 270 µm. The development of the larval shell and larval hinge of the mollusc is considered in detail. The development of the larval shell of C. ciliatum is similar to the development of other family members. Throughout all the larval stages, the shell has a rounded shape with a low umbos, and the prodissoconch II has a clearly visible concentric structure. The C. ciliatum larval hinge is characterized by weak differentiation and the absence of pronounced cardinal teeth typical for other Cardiidae. However, the lateral structures of the castle – ridges and flanges – are well developed. The ligament begins to form at a size of 240–250 µm and occupies a lateral position. The settlement of the cockle takes place in September in the subtidal zone. After the metamorphosis, a large radial sculpture is formed on the dissoconch and a number of small spikes are formed at the rib of the posterior shoulder.

Cassiavellia galtarae, new species, new genus: a new Permian bivalve and its significance for pterioidean systematics

2010 ◽  
Vol 84 (6) ◽  
pp. 1152-1176 ◽  
Author(s):  
Ilya Tëmkin ◽  
John Pojeta
Keyword(s):  
New Species ◽  
New Genus ◽  
Larval Shell ◽  
Upper Permian ◽  
Taxonomic Significance ◽  
New Genus And Species ◽  
The Family ◽  
Dental Ontogeny

An exceptionally well-preserved silicified bivalve from the Upper Permian of Texas is described and assigned to a new genus and species,Cassiavellia galtarae, placed in the family Bakevelliidae. The species represents one of the earliest and best characterized unequivocal occurrences of the multivincular ligament in the superfamily Pterioidea. The silicified material provides a wealth of information on the morphology of inadequately known Paleozoic pterioideans, including hitherto undescribed aspects of the larval shell, auricular sulcus, muscle scars, and dental ontogeny. The discovery of the condyle-fossa complex on the anteroventral shell margin, a feature previously undescibed in Bivalvia, raises the question of the homology and taxonomic significance of the problematic subumbonal ridge-like structures in Pterioidea. In life,C. galtaraewas probably an epifaunal right-pleurothetic bivalve, byssally attached to hard or raised flexible substrata. In addition toC. galtarae, another new species,C. nadkevnae, is placed inCassiavellia.

scholarly journals A 5000-YEAR FOSSIL RECORD OF LARVAL SHELL MORPHOLOGY OF SUBMARINE CAVE MICROSHELLS

Evolution ◽  
2009 ◽  
Vol 63 (1) ◽  
pp. 295-300 ◽  
Author(s):  
Takao Ubukata ◽  
Akihisa Kitamura ◽  
Mayumi Hiramoto ◽  
Tomoki Kase
Keyword(s):  
Fossil Record ◽  
Shell Morphology ◽  
Larval Shell ◽  
Submarine Cave

A primitive Halobia (Bivalvia: Halobioidea) from the Triassic of northeast British Columbia

2000 ◽  
Vol 74 (4) ◽  
pp. 599-603 ◽  
Author(s):  
Christopher A. Mcroberts
Keyword(s):  
British Columbia ◽  
New Species ◽  
Shell Morphology ◽  
Larval Shell ◽  
Developmental Strategy ◽  
Widespread Distribution ◽  
Dispersal Mechanism ◽  
Sudden Appearance ◽  
External Ornamentation

Halobia daonellaformis new species is described from the lowermost Carnian of northeast British Columbia. Halobia daonellaformis n. sp. is regarded as a primitive Halobia characterized by external ornamentation similar to Daonella lommeli, but with a poorly developed anterior auricle. Morphologic characters of H. daonellaformis n. sp. suggest that Halobia may be not a natural taxon but a polyphyletic group with one or more ancestors from Daonella and Aparimella and/or other posidoniid(s). The sudden appearance of Halobia throughout the marine Triassic suggests a rapid dispersal mechanism following a Ladinian origin. Larval shell morphology indicates a planktotrophic developmental strategy for H. daonellaformis n. sp., and by extension to other halobiids, which may explain the widespread distribution of many halobiid species.

An analysis of bivalve larval shell pigments using micro-Raman spectroscopy

2014 ◽  
Vol 45 (5) ◽  
pp. 349-358 ◽  
Author(s):  
Christine M. Thompson ◽  
Elizabeth W. North ◽  
Sheri N. White ◽  
Scott M. Gallager
Keyword(s):  
Raman Spectroscopy ◽  
Larval Shell ◽  
Micro Raman Spectroscopy

A review of the early life history of zebra mussels (Dreissena polymorpha): comparisons with marine bivalves

1994 ◽  
Vol 72 (7) ◽  
pp. 1169-1179 ◽  
Author(s):  
Josef Daniel Ackerman ◽  
Blair Sim ◽  
S. Jerrine Nichols ◽  
Renata Claudi
Keyword(s):  
Life History ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Early Life History ◽  
Zebra Mussels ◽  
Larval Shell ◽  
Planktonic Larva ◽  
External Fertilization ◽  
Marine Bivalves ◽  
History Of

The ecological and economic impacts of the introduced zebra mussel (Dreissena polymorpha (Pallas)) have been due in part to a life history that is conserved with marine bivalves but unique among the indigenous freshwater fauna. There are a number of life history events in D. polymorpha that follow external fertilization and embryology. The first is a brief trochophore stage. The development of a velum and secretion of a larval shell lead to a D-shaped veliger, which is the first recognizable planktonic larva. Later a second larval shell is secreted and this veliconcha is the last obligate free-swimming veliger. Conversely, the last larval stage, the pediveliger, can either swim using its velum or crawl using its foot. Pediveligers select substrates on which they "settle" by secreting byssal threads and undergo metamorphosis to become plantigrade mussels. The secretion of the adult shell and change in growth axis lead to the convergent heteromyarian shape. Zebra mussels produce byssal threads as adults, but these attachments may be broken, enabling the mussels to translocate to new areas. The recognition of these life history features will lead to a better understanding of zebra mussel biology. In summary, life history stages of zebra mussels are similar to those of marine bivalves and should be identified morphologically rather than on the basis of size.

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