Structural analysis of the digestive gland of the queen conch Strombus gigas Linnaeus, 1758 and its intracellular parasites

Morphology and Cyclic Activity of the Digestive Gland ofZidona dufresnei(Caenogastropoda: Volutidae)

“…The tubules of the digestive gland of Z. dufresnei shared some characteristics with the digestive tubules in Aplysia punctata (Cuvier, 1803) (Taïeb & Vicente, 1999;Taïeb, 2001) and Strombus gigas (Linnaeus, 1758) (Gros et al, 2009) in that two different type of digestive tubules with different cell types were present. In Z. dufresnei, tubules of type 1 were formed by an epithelium containing two cell types: digestive and basophilic cells, as in most other gastropods that have been studied (Morton, 1955;Merdsoy & Farley, 1973;Reader, 1976;Wigham, 1976;Nelson & Morton, 1979;Dimitriadis & Andrews, 2000;Baqueiro Cárdenas et al, 2007;Gros et al, 2009;.…”

“…In Z. dufresnei, tubules of type 1 were formed by an epithelium containing two cell types: digestive and basophilic cells, as in most other gastropods that have been studied (Morton, 1955;Merdsoy & Farley, 1973;Reader, 1976;Wigham, 1976;Nelson & Morton, 1979;Dimitriadis & Andrews, 2000;Baqueiro Cárdenas et al, 2007;Gros et al, 2009;. The type 2 tubules of Z. dufresnei are exclusively composed of basophilic cells and different stages are not observed in these cells as in A. punctata (Taïeb, 2001).…”

“…Most studies of the histology of the molluscan digestive gland have been conducted on bivalves (Owen, 1970;Thompson et al, 1 Logan et al, 2008) and herbivorous microphagous gastropods (Merdsoy & Farley, 1973;Boghen & Farley, 1974;Reader, 1976;Wigham, 1976;Nelson & Morton, 1979;Taïeb & Vicente, 1999;Lobo-da-Cunha, 1999, 2000Taïeb, 2001;Baqueiro Cárdenas et al, 2007;Gros et al, 2009;. However, a study by Dimitriadis & Andrews (2000) on the neogastropod Nucella lapillus (Linnaeus, 1758) has provided the only report of the functional morphology of the digestive gland of a carnivorous caenogastropod.…”

Attenuated reproduction of Strombus gigas by an Apicomplexa: Emeriidae-like parasite in the digestive gland

“…The number of parasites in the digestive gland varied with time (Table 1), apparently synchronizing with physiological cycle of the digestive gland (Gros et al, 2009). But it is the abundance of Merozoites, the trophic stage, that most influences reproductive failure .…”

Occurrence of Apicomplexa-like structures in the digestive gland of Strombus gigas throughout the Caribbean

“…The most common stage observed was the sporocyst but their abundance varies with localities, which may be influenced by prevailing environmental conditions. It is also possible that variations in abundance might be associated to the physiological stage of the digestive gland of conchs, talking advantage of the renewal of the digestive cell (Gros et al, 2009).…”