The structure, ciliation, and function of the lips of some bivalve molluscs

1974 ◽  
Vol 52 (3) ◽  
pp. 335-343 ◽  
Author(s):  
T. H. J. Gilmour
Keyword(s):  
Suspension Feeding ◽  
Bivalve Molluscs ◽  
Food Material ◽  
Water Currents ◽  
Excess Water ◽  
And Function

The structure, ciliation, and function of the lips of 12 species belonging to nine families of the subclass Pteriomorphia are described. All these species have devices for preventing the swallowing of excess water, collected along with participate food material, by the ctenidia and palps. It is suggested that in all bivalves, as in other suspension-feeding animals, water currents are generated by the food-collecting apparatus. But, whereas in members of the echinoderm superphylum, the development of gill slits to allow the escape of excess water which has already entered the mouth has had great evolutionary implications, the escape of water before it gets to the mouth is usually achieved in a less conspicuous manner in bivalves, although a complex lip apparatus has been developed in some monomyarian members of the Pteriomorphia.

Ciliation and function of the food-collecting and waste-rejecting organs of lophophorates

1978 ◽  
Vol 56 (10) ◽  
pp. 2142-2155 ◽  
Author(s):  
T. H. J. Gilmour
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Waste Material ◽  
Suspension Feeding ◽  
Food Material ◽  
Water Currents ◽  
Excess Water ◽  
Transmission Electron ◽  
Food Particles ◽  
And Function

Experiments with mixtures of colloidal graphite, stained Sephadex particles, and algae; observations by stroboscopic interference contrast optics; and scanning and transmission electron microscopy suggest that phoronids, brachiopods, and bryozoans can simultaneously reject waste material by an impingement mechanism and accept edible particles by a filtration mechanism without the ciliary reversals suggested in previous models of suspension feeding in lophophorates. Specialized laterofrontal cilia, which may detect heavy inedible particles, are found on the tentacles of all three phyla of lophophorates. In phoronids and bryozoans edible material is carried towards the esophagus by components of water currents created by the lateral cilia of the tentacles of the lophophore while inedible particles are rejected by the frontal cilia of the tentacles. The passage of food material to the mouths of brachiopods is assisted by frontal cilia located in grooves on alternate tentacles while the frontal cilia of ungrooved tentacles reject inedible material. The epistomes of lophophorates are also involved in the simultaneous acceptance of food and rejection of solid waste material and allow the escape of excess water travelling towards the mouth with food particles. This finding of a functional significance for the epistome suggests that lophophorates deserve reassessment as possible ancestors of chordates.

Feeding in tornaria larvae and the development of gill slits in enteropneust hemichordates

1982 ◽  
Vol 60 (12) ◽  
pp. 3010-3020 ◽  
Author(s):  
T. H. J. Gilmour
Keyword(s):  
Body Wall ◽  
Dorsal Surface ◽  
Structure And Function ◽  
The Body ◽  
Flow Lines ◽  
Water Currents ◽  
Larval Stages ◽  
Excess Water ◽  
Preoral Lobe ◽  
And Function

The food-collecting and waste-rejecting systems of the tornaria larval stages of enteropneust hemichordates are similar to those of larval and adult lophophorates and adult pterobranch hemichordates. Water entering the oral grooves is deflected towards the mouth and the impetus of heavy, potentially inedible particles may take them across the flow lines of the water currents inferred from the movements of suspended particles to impinge on cilia which reject them into the outgoing water currents. Lighter, potentially edible material remaining suspended in the deflected water currents is intercepted by cilia on an oral hood which is similar in structure and function to the preoral lobe of the actinotroch larvae of phoronids. Excess water carried into the mouth by cilia on the dorsal surface of the esophagus is rejected via lateral grooves which develop into pouches prior to metamorphosis. Following metamorphosis the pouches make contact with the body wall to form gill slits which continue to allow water to escape from the pharynx. This finding that the function of allowing excess water to escape is performed by lateral grooves in the esophagus of tornariae supports previous speculations on the evolution of gill slits and provides further evidence for relationships between lophophorates, hemichordates, and chordates.

A NEWIN SITUMETHOD FOR MEASURING SESTON UPTAKE BY SUSPENSION-FEEDING BIVALVE MOLLUSCS

2006 ◽  
Vol 25 (2) ◽  
pp. 643-649 ◽  
Author(s):  
RAYMOND E. GRIZZLE ◽  
JENNIFER K. GREENE ◽  
MARK W. LUCKENBACH ◽  
LOREN D. COEN
Keyword(s):  
Suspension Feeding ◽  
Bivalve Molluscs

scholarly journals Paleoecologic implications of epibionts on the Silurian lichid trilobite Arctinurus

1992 ◽  
Vol 6 ◽  
pp. 289-289 ◽  
Author(s):  
Denis K. Tetreault
Keyword(s):  
New York ◽  
New York State ◽  
Sediment Surface ◽  
Suspension Feeding ◽  
Dorsal Shield ◽  
Age Classes ◽  
York State ◽  
Water Currents ◽  
Circulation Patterns ◽  
Long Life

The Wenlockian lichid trilobite Arctinurus boltoni has been regarded as a classic example of a “snow-shoe” type adaptation. That is, the broad flat doublure has been interpreted as a resting surface, with well-developed terrace ridges serving as either sensory or frictional devices. New data from the Rochester Shale of western New York State indicate that this interpretation is incorrect The discovery of the small, calcareous worm tube Cornulites on complete, articulated specimens of Arctinurus indicates that these trilobites seldom rested their doublure on the sediment surface. Apertures of all specimens of Cornulites are oriented posteriorly, suggesting a rheophilic response to persistent water circulation patterns beneath the trilobite. The presence of suspension feeding organisms on the doublure also indicates that the water currents beneath the trilobite were free of suspended mud, so that Arctinurus may not have processed sediment in search of food.Large specimens of Arctinurus also have numerous epibionts on the dorsal shield, including cyclostome bryozoans, brachiopods (Stegerhynchus) and Cornulites. The presence of these suspension feeders indicates that Arctinurus did not burrow or even partially cover itself with mud. The large number of epibionts on adult specimens of Arctinurus, including several age classes for Stegerhynchus, indicates that molting stopped or at least slowed greatly once a certain size was attained, and that these trilobites may have had fairly long life spans.

Comparative physiology of suspension-feeding in living brachiopods and bivalves: evolutionary implications

Paleobiology ◽  
1993 ◽  
Vol 19 (3) ◽  
pp. 322-334 ◽  
Author(s):  
Melissa Clark Rhodes ◽  
R. J. Thompson
Keyword(s):  
Body Size ◽  
Fossil Record ◽  
Benthic Communities ◽  
Suspension Feeding ◽  
Metabolic Rates ◽  
Comparative Physiology ◽  
Feeding Rates ◽  
Bivalve Molluscs ◽  
Significant Component ◽  
Experimental Conditions

This paper presents scaling equations relating suspension-feeding rates to body size for articulate brachiopods and bivalve molluscs, two classes which represent a significant component of the fossil record of marine benthic communities. Clearance (feeding) rates of five species of living articulate brachiopods and three species of epifaunal suspension-feeding bivalve molluscs collected from mid-latitude fjords of Newfoundland and New Zealand were measured in similar experimental conditions. In comparisons within and between the two classes, we found that both plectolophous and spirolophous brachiopods had significantly lower feeding rates than mytilids, which are filibranchs, but that a sympatric primitive eulamellibranch veneroid bivalve had rates comparable to the brachiopods. Articulate brachiopods do not appear to feed effectively at the high algal concentrations which bivalves can exploit. The data on comparative suspension-feeding rates support the hypothesis that past changes in diversity and distribution of bivalves and brachiopods may be related to an overall increase in energy flux and escalation of metabolic rates during the Phanerozoic.

scholarly journals The utility of in vivo observations for describing particle capture processes in suspension-feeding bivalve molluscs

2000 ◽  
Vol 45 (5) ◽  
pp. 1203-1210 ◽  
Author(s):  
J. E. Ward ◽  
L. P. Sanford ◽  
R. I. E. Newell ◽  
B. A. MacDonald
Keyword(s):  
Suspension Feeding ◽  
Bivalve Molluscs ◽  
Particle Capture

A neuronal mechanism for the control of latero-frontal ciliary activity in the fingernail clam, Musculium transversum

1983 ◽  
Vol 41 ◽  
pp. 658-659
Author(s):  
Anthony Paparo ◽  
Judith A. Murphy ◽  
Robert Dean
Keyword(s):  
Ciliated Cell ◽  
Ciliary Activity ◽  
Suspension Feeding ◽  
Control Mechanisms ◽  
Nerve Supply ◽  
Ciliated Cells ◽  
Bivalve Molluscs ◽  
Neuronal Mechanism ◽  
Gill Filaments ◽  
Fingernail Clams

Extensive studies have dealt with the transport of particles on the gill of suspension feeding bivalves, but our knowledge of the mechanisms involved is still incomplete. There is, however, physiological evidence that each of the ciliated cell systems in bivalve molluscs may be individually controlled. Three types of ciliated cells are distinguished on the gill of fingernail clams: frontal (FC); latero-frontal (LFC); and lateral (LC).For the most part in studies involving ciliary control mechanisms, LFC are neglected. It is thus the purpose of this study to present data which begin to elucidate a neuronal mechanism for LFC control.Gill preps were isolated with an intact nerve supply in a dish which was placed in a holder fastened to an adjustable stage of a microscope. In fields of view of 50 gill filaments, ciliary motility, chemical perfusion and electrical stimulation were observed and/or performed.

scholarly journals Selective Capture and Ingestion of Particles by Suspension-Feeding Bivalve Molluscs: A Review

2018 ◽  
Vol 37 (4) ◽  
pp. 727-746 ◽  
Author(s):  
Maria Rosa ◽  
J. Evan Ward ◽  
Sandra E. Shumway
Keyword(s):  
Suspension Feeding ◽  
Bivalve Molluscs
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