Regeneration of the Inhalant Siphon ofMesodesma mactroides(Deshayes, 1854) (Mollusca: Bivalvia)

Malacologia ◽  
2010 ◽  
Vol 52 (1) ◽  
pp. 175-179 ◽  
Author(s):  
Jesús D. Nuñez ◽  
Marcelo A. Scelzo ◽  
Maximiliano Cledón
Keyword(s):  
Inhalant Siphon

The distribution and density of ciliary tufts on the siphons of Anodonta cygnea (Mollusca: Bivalvia)

1990 ◽  
Vol 48 (3) ◽  
pp. 518-519
Author(s):  
Wen-lung Wu
Keyword(s):  
Osmium Tetroxide ◽  
Internal Surface ◽  
Mechanical Stimuli ◽  
Type Ii ◽  
Sensory Receptors ◽  
Anodonta Cygnea ◽  
Type Iv ◽  
Sem Study ◽  
Inhalant Siphon ◽  
Type V

The mantle of bivalves has come entirely to enclose the laterally compressed body and the mantle margin has assumed a variety of functions, one of the pricipal ones being sensory. Ciliary tufts, which are probably sensory, have been reported from the mantle and siphons of several bivalves1∽4. Certain regions of the mantle margin are likely to be more or less, sensitive to certain stimuli than others. The inhalant siphon is likely to be particularly sensitive to both chemical and mechanical stimuli, whereas the exhalant siphon will be less sensitive to both. The distribution and density of putative sensory receptors on the in-and ex-halant siphon is compared in this paper.The excised siphons were fixed in glutaraldehyde and osmium tetroxide, the whole procedure of SEM study is recorded in Wu's thesis.Type II cilia cover the tips of tentacles, 6.13um. Type IV and type V cilia are found on the surface of tentacles. Type IV cilia are occasionally present at the tips of tentacles, 8 um long. They are the commonest type on the surface of tentacles. Type VI cilia occor in the internal surface of the inhalant siphon, but are not found on the surface of tentacles, 6.7-10um long.

Development of mantle organs, feeding, and locomotion in postlarval Macoma balthica (L.) (Lamellibranchiata)

1969 ◽  
Vol 47 (4) ◽  
pp. 609-617 ◽  
Author(s):  
J. F. Caddy
Keyword(s):  
Shell Length ◽  
Macoma Balthica ◽  
Adult Form ◽  
Form And Function ◽  
Mantle Edge ◽  
Inhalant Siphon ◽  
And Function ◽  
Development Proceeds

Postlarval M. balthica is well adapted for interstitial life in a particulate sediments, although metamorphosis to the adult form and function is not complete until a shell length of 2 mm is reached.Spatfall at 300–310 μ shell length is followed by a plantigrade stage in which the ciliated plantiform foot is used as an organ of feeding, locomotion, and rejection of pseudofaeces. The inhalant current is produced by the ciliation of the foot and inner demibranch, and enters through the pedal gape. This is already separated from the lumen of the inhalant siphon by the cruciform apparatus. Food sorting in the early postlarvae is exclusively by the palps, which are well developed in the midline to overhang the mouth, and already have simple sorting ridges on their inner surfaces.Siphon development proceeds by infolding of the fusions of the mantle edge around the siphonal apertures. In early postlarvae the pseudofaeces are transported to the pedal gape by the mantle ciliary tract, and swept from the mantle edge by the foot. At approximately 1 mm shell length, rejection of pseudofaeces occurs via the inhalant siphon, which only gradually takes over its adult function as exclusive route of the inhalant current at between 1 and 2 mm.

A new genus Turneroconcha (Bivalvia: Vesicomyidae: Pliocardiinae) for the giant hydrothermal vent clam ‘Calyptogena’ magnifica

Zootaxa ◽  
2020 ◽  
Vol 4808 (1) ◽  
pp. 79-100 ◽  
Author(s):  
ELENA M. KRYLOVA ◽  
HEIKO SAHLING
Keyword(s):  
Morphological Analysis ◽  
New Genus ◽  
Posterior Part ◽  
Morphological Characters ◽  
Morphological Data ◽  
Monotypic Genus ◽  
East Pacific ◽  
Inhalant Siphon ◽  
The Right ◽  
Galapagos Rift

A new monotypic genus, Turneroconcha, is established for T. magnifica (Boss & Turner) which was originally assigned to the genus Calyptogena Dall. The distinguishing morphological characters of the new genus are the combination of both conchological and anatomical features including: the presence of only two tooth elements in the right valve; submerged location of the posterior part of the posterior lamellar ligament layer; the absence of a subumbonal pit, lunular incision, escutcheon and pallial sinus; the presence of both pairs of demibranchs; the tubular structure of marginal parts of the interlamellar septa in gills; an inner valve of the inhalant siphon without processes; tentaculate inner mantle fold 3 and a Z-shaped digestive tract. Analysis of morphological data on Recent and fossil pliocardiines shows that Turneroconcha gen. nov. can be presently considered as a monotypic genus. The comparative morphological analysis of the new genus with described pliocardiine genera is consistent with available molecular results. Turneroconcha gen. nov. is endemic to the East-Pacific Rise and Galapagos Rift and occurs at water depths of 2251 to 2791 m. It is the only pliocardiine genus known so far with a mainly epifaunal life habit. No fossils of Turneroconcha gen. nov. are known.  

The mechanism of boring in Zirphaea crispata (L.) (Bivalvia: Pholadidae)

1968 ◽  
Vol 170 (1019) ◽  
pp. 155-173 ◽  
Keyword(s):  
Adductor Muscle ◽  
Mantle Cavity ◽  
Clockwise Rotation ◽  
Mantle Tissue ◽  
Counter Pressure ◽  
Time Period ◽  
Adductor Muscles ◽  
Inhalant Siphon ◽  
Main Activity ◽  
Low Pressures

The main activity during boring by Zirphaea crispata consists of the cyclical repetition of a group of movements, termed the boring cycle. Each boring cycle comprises the retraction of the shell to the base of the burrow, and the abrasion of the walls of the burrow by movements of the shell caused by the consecutive action of the posterior and anterior adductor muscles, supplemented by an accessory ventral adductor muscle. Each boring cycle is followed by slight anticlockwise and clockwise rotation of the animal in the burrow, while simultaneously the siphons are withdrawn and re-extended. A second type of rotational movement, resulting from changes in the position of the foot in the burrow, occurs over a longer time period, so that a circular, drop-shaped burrow is formed. The material abraded from the base of the burrow is collected into the mantle cavity and ejected as pseudofaeces from the inhalant siphon at intervals during boring. The pressures developed in the mantle cavity and haemocoele during boring are small compared with those generated by burrowing forms. During the boring cycle, low pressures (2 to 3 cm) serve to press the foot against the wall of the burrow where adhesion is aided by mucous secretion and by the action of a counter pressure from a pad of mantle tissue dorsally. Fluid is retained in the foot, and in the expanded mantle margins within the spaces of a loosely arranged connective tissue which fills these organs. The fluid filled mantle cavity and haemocoele allow the siphonal retractor muscles to act partly in antagonizing the adductor muscles, so that withdrawal of the siphons during boring restores the gape of the shell. Higher pressures (8 cm) are developed in the mantle cavity and haemocoele during the contraction of the adductor muscles and circular muscles of the siphons which is involved in the expulsion of pseudo-faeces. The tensions exerted by the pedal muscles during boring are small (2 to 2·5 g).

The feeding mechanism of Yoldia ( ═ Aequiyoldia ) eightsi (Courthouy)

1988 ◽  
Vol 232 (1269) ◽  
pp. 431-442 ◽  
Keyword(s):  
Posterior Part ◽  
Dry Mass ◽  
Mantle Cavity ◽  
Bivalve Mollusc ◽  
Suspension Feeder ◽  
Surface Layers ◽  
Processed Material ◽  
Ciliary Action ◽  
Inhalant Siphon ◽  
Mass Basis

The protobranch bivalve mollusc Yoldia eightsi Courthouy is both a deposit feeder (on mud) and a suspension feeder (on diatoms in the ventilatory streams, which are trapped on the ctenidia). The species has a similar anatomy to other Yoldia species, but is a more shallow burrower which adopts a more horizontal shell orientation than the vertically burrowing Yoldia limatula and Yoldia ensifera . Although capable of feeding on the surface layers of mud by extending its palp proboscides outside the partly buried shell, Yoldia eightsi spends most of its time feeding while totally buried. To do this, sediment is taken into the mantle cavity by opening the shell valves, or by foot movements. The sediment is moved by ciliary action to the posterior part of the mantle cavity where it forms a compact, mucus-coated sediment slug. The slug is repeatedly sorted largely by the palp proboscides, fine material being transferred to the mouth via the palps. Sorting appears to be done on a simple size–density basis, with large, dense particles being rejected. After sorting, the inorganic fraction of the slug is expelled through the inhalant siphon (‘pseudofaecal plume’). Expulsions occur every 6–35 min. True faeces (‘faecal plume’) are expelled much more frequently in the expiratory bursts of water from the exhalant siphon. Pseudofaecal output is about 170 times the faecal output (on a dry mass basis), suggesting that Yoldia eightsi ingests 0.6% of processed material.

On the Habits and Adaptations of Aloidis (Corbula) Gibba

1946 ◽  
Vol 26 (3) ◽  
pp. 358-376 ◽  
Author(s):  
C. M. Yonge
Keyword(s):  
Great Reduction ◽  
Inorganic Material ◽  
Left Valve ◽  
Byssus Thread ◽  
Adductor Muscles ◽  
Inhalant Siphon ◽  
The Asymmetry ◽  
The Right ◽  
Marginal Region

1. Aloidis (Corbula) gibba is a eulamellibranch specialized for life in muddy gravel substrata to depths of up to about 80 fathoms.2. The shell is asymmetrical, the margin of the smaller, left valve being uncalcified and so fitting within the marginal region of the right valve. A possible manner in which this asymmetry is produced by the differential secretory activities of the two mantle edges is discussed.3. The marginal periostracum of the left valve has strengthening calcined regions posteriorly, probably to protect the siphons when extruded.4. The external ligament is reduced and the resilium condensed, possibly permitting some antero-posterior rocking of the shell valves when the adductors contract.5. The process of burrowing is described; on its completion the animal is anchored by a single byssus thread.6. The siphons are very short, the tentacles of the siphonal sheath lying on the surface of the substratum. The inhalant siphon is wide and relatively insensitive; it draws in much bottom material. The exhalant siphon is tubular and very sensitive. It is controlled by two paired bands of muscle.7. The great quantities of pseudo-faeces which accumulate are expelled by periodical contractions of the 'quick' portions of the adductor muscles, the asymmetry of the shell valves causing great reduction in the size of the inhalant chamber. The foot may also assist in clearing the chamber. 8. The large ctenidia create a very powerful current; they are adapted for dealing with large amounts of sediment by means of specialized terminal, guarding and cirrus-like cilia. Control of 'pumping' is primarily by means of the exhalant siphon.9. The stomach is large in correlation with the great amounts of inorganic material carried in with the food.

The biology and functional morphology of the predatory septibranch Cardiomya costellata (Deshayes, 1833) (Bivalvia: Anomalodesmata: Cuspidariidae) from the Acores: survival at the edge

2015 ◽  
Vol 96 (6) ◽  
pp. 1347-1361 ◽  
Author(s):  
Brian Morton
Keyword(s):  
Functional Morphology ◽  
Shell Length ◽  
Reproductive Strategy ◽  
Anatomical Study ◽  
Hydrodynamic Forces ◽  
Simultaneous Hermaphrodite ◽  
Post Mortem ◽  
Potential Prey ◽  
North Eastern ◽  
Inhalant Siphon

This is the first comprehensive anatomical study of a representative of the septibranch Cuspidariidae. Particular interest in Cardiomya costellata is related to the fact that only two species of such predatory septibranchs have been recorded from the remote Açorean Archipelago and, here, individuals of both taxa are half the shell length of conspecifics throughout the species’ North-eastern Atlantic range. The shell of C. costellata is thin, fragile and rostrate. This latter attribute allows the inhalant siphon (as in other cuspidarioids) to be extended towards potential prey to effect their capture. How this extension is effected has been described but, herein, the hydrodynamic forces needed to achieve this are put into a firmer anatomical context. Uniquely amongst the Anomalesmata, cuspidarioids have, previously, been regarded as dioecious. This is not the case for C. costellata, which is a protandric consecutive hermaphrodite. The gonads and reproductive strategy of this species are compared with those of the spheniopsid Grippina coronata that is representative of a second cuspidarioid family of deeper water predators and which is a simultaneous hermaphrodite brooding self-fertilized embryos in the gonadial follicles with their release being post mortem. Some evidence suggests that in the Açores, the possible crustacean prey of C. costellata are also smaller than their mainland conspecifics, which, when viewed in the overall context of the predator's biology and anatomy, might explain its poor success in the oligotrophic waters of these mid-Atlantic islands.

The raptorial siphonal apparatus of the carnivorous septibranch Cardiomya planetica Dall (Mollusca:Bivalvia), with notes on feeding and digestion

1980 ◽  
Vol 58 (4) ◽  
pp. 670-679 ◽  
Author(s):  
Robert G. B. Reid ◽  
Suzin Porteous Crosby
Keyword(s):  
Blood Pressure ◽  
Sensory Input ◽  
Inhalant Siphon ◽  
Sensory Mechanism

Cardiomya planetica Dall is a carnivorous septibranch bivalve. The food-capturing organ is the inhalant siphon, which can be rapidly extended by a surge of blood. The increase in blood pressure is brought about by the contraction of the septum. The sensory mechanism is constituted by seven siphonal tentacles with mechanoreceptors at their tips. The mechanoreceptors are composed of clumps of clubbed cilia in apical pits lined with microvilli. The activity of the septum, inhalant siphon, and pallial valve is coordinated with the sensory input through a large siphonal ganglion. Food consists largely of ostracods and digestion appears to be periodic.

The mechanisms of boring in Martesia striata Linné (Bivalvia: Pholadidae) and Xylophaga dorsalis Turton (Bivalvia: Xylophaginidae)

1969 ◽  
Vol 174 (1034) ◽  
pp. 123-133 ◽  
Keyword(s):  
Cross Section ◽  
Circular Cross Section ◽  
Mantle Cavity ◽  
Body Fluids ◽  
The Body ◽  
Clockwise Rotation ◽  
Faecal Pellets ◽  
Adductor Muscles ◽  
Inhalant Siphon ◽  
Wood Boring

Penetration of timber by the wood-boring bivalves Martesia striata and Xylophaga dorsalis is effected by means of the cyclical repetition of a group of movements termed the boring cycle. In Martesia the boring cycle comprises first the retraction of the shell to the base of the burrow, followed by the abrasion of the wall of the burrow by movements of the shell caused by a single consecutive contraction of each of the adductor muscles. In Xylophaga similar movements are involved, but the boring cycle in this species has become elaborated by repetition of the contractions of the adductor muscles which may be repeated to give a series of up to 24 rocking movements of the shell about a dorso-ventral axis. In both species the boring cycle may be followed by movements involving anti-clockwise and clockwise rotation in the burrow, while simultaneously the siphons are partially withdrawn and re-extended; in both, longer term rotations in the burrow result in the production of a drop-shaped burrow of circular cross-section. In both species the material abraded from the base of the burrow is collected into the mantle cavity; in Martesia it is then ejected as pseudofaeces through the inhalant siphon at intervals during boring, while in Xylophaga a larger proportion passes into the gut and eventually collects in the form of faecal pellets to form a plug to the burrow. The pressures developed in the mantle cavity and haemocoele during boring are small compared to those in burrowing forms, but of the same order as those recorded from the related rock-boring pholad Zirphaea crispata , and it is concluded that the body fluids play a decreasing hydraulic role as specialization for boring increases.

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