Summary
Physical Description
Ecology
Local Distribution - Mini Report
Life History & Behaviour
Reproduction
Respiration and Feeding
Movement
Anatomy & Physiology
External Morphology
Internal Anatomy
Evolution & Systematics
Biogeographic Distribution
Conservation & Threats
References & Links | Internal Anatomy
Gills
The lamellibranch gills are an important adaptation of the bivalve molluscs, allowing a release from deposit-feeding and enabling filter-feeding to occur. There are three types of lamellibranch gills; filibranch, pseudolamellibranch and eulamellibranch gills. Eulamellibranch gills are the most complex and are the type of gills seen in Scintilla spp. Figure 1 shows the general lamellibranch system where each gill filament branches off the central axis, consisting of an ascending and descending limb. The figure has been stylised to illustrate the structure however in reality the gill filaments are very close together, forming a lamellae through which water flows. The lamellae acts to trap food particles while frontal cilia direct them into food grooves to be transported to the digestive system.
Figure 1: Lamellibranch gill system in molluscs. Adapted from Ruppert, Fox and Barnes
Attachment to Substrate
Scintilla spp. is primarily a sessile organism, attaching to the coral rubble substrate using its byssus, located just next to the foot. The byssus is a bunch of strong protein threads which are made by the byssal glands secreting a liquid which is shaped into threads by the byssal groove then stuck to the substrate (Figure 1).
Figure 2: The byssus of Scintilla spp. for attachment to substrate. Adapted from Ruppert, Fox and Barnes
General Bivalve Anatomy
The digestive system consists of the mouth, oesophagus, intestine, stomach, rectum and anus. Labial palls are used to sort food from mineral particles that are caught within the lamellae.
The posterior and anterior adductor muscles (Figure 4) extend between the two valves and in conjunction with the hinge ligaments are responsible for closing the valves. For Scintilla spp. heterodont (specialised) teeth line the edges of the valves to prevent slippage and cleavage of the valves.
Figure 3: Scintilla spp. with the valves removed
Figure 4: General Bivalve internal Anatomy. Adapted from Ruppert, Fox & Barnes |
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