Source and Fate of the Zooxanthellæ of the Visceral Mass of Tridacna elongata

Mansour, K.

doi:10.1038/158130a0

Cited by 18 publications

(4 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the algal symbionts are in blood sinuses, they might be expected in other areas of the clam through which blood circulates. Indeed, Yonge (1936) observed zooxanthellae in the gills and the heart tissue, but Mansour (1946b) could not corroborate his observations. We saw zooxanthellae in the ventricle and in a vessel passing through the kidney (Fig.…”

Section: Discussionmentioning

confidence: 90%

See 1 more Smart Citation

Observations on the Symbiosis With Zooxanthellae Among the Tridacnidae (Mollusca, Bivalvia)

Trench¹,

Wethey²,

Porter³

1981

The Biological Bulletin

132

View full text Add to dashboard Cite

The symbiosis with zooxanthellae among tridacnid bivalve molluscs has been examined in order to assess the morphological relation of the algae to the hosts' tissues and the dynamics of the interactions between the algae and the clams.Light and electron microscopic evidence indicates that the zooxanthellae located in the haemal sinuses of the hypertrophied siphon are intercellular in all six tridacnid species studied. The algae pass from the siphonal tissues to the alimentary tract from which they are voided as feces. Many of the defecated symbionts are morphologically intact and photosynthetically functional. The concretions in the kidneys of tridacnids, previously thought to be the indigestible remains of zooxanthellae, are identified as phosphorite deposits, which are not unique to tridacnids.Analyses of photosynthesis-radiant flux relations in Tridacna maxima indicate that over 24 h the algae produce more oxygen than is consumed by the association, and estimates suggest that the algae may contribute more than 50% of the animals' metabolic carbon requirements.

show abstract

Section: Discussionmentioning

confidence: 90%

“…In his early reports, Mansour (1946b) described intact zooxanthellae and zooxanthellae in various stages of degradation in the alimentary tract of T. elongata (= maxima). Yonge (1936) had also observed these, but concluded that they were artifactual, resulting from damage to the clams during handling.…”

Section: Discussionmentioning

confidence: 99%

Observations on the Symbiosis With Zooxanthellae Among the Tridacnidae (Mollusca, Bivalvia)

Trench¹,

Wethey²,

Porter³

1981

The Biological Bulletin

132

View full text Add to dashboard Cite

show abstract

“…The mantle The exposed siphonal tissues house innumerable zooxanthellae (Yonge, 1936(Yonge, , 1953Mansour, 1945Mansour, , 1946Kawaguti, 1966;Fankboner, 1971 ;Goreau, Goreau & Yonge, 1973).…”

Section: Results the Diurnal Rhythm Of Activity And Inactivitymentioning

confidence: 99%

The diurnal rhythm and the processes of feeding and digestion in Tridacna crocea (BivaMa: Tridacnidae)

Morton

1978

Journal of Zoology

View full text Add to dashboard Cite

Tridacna crocea Lamarck 1819 possesses a diurnal rhythm of activity. During the daylight hours the hypertrophied siphonal tissues, containing zooxanthellae, are expanded and phasic adductions occur that pump fresh sea water into and filtered water and pseudofaeces out of the mantle cavity. During the night the shell valves become more apposed, the mantle folds are withdrawn and few phasic adductions occur. Such a pattern of activity is similar to that described for other sublittoral bivalves. With this cycle of activity and inactivity is correlated the process of extra‐cellular digestion of filtered food in the stomach. This is accomplished by the alternate, but incomplete, dissolution and subsequent reformation of the crystalline style. The style partially dissolves at night and reforms during the day. The digestive diverticula undergo a sequence of cytological changes related to the intra‐cellular digestion of filtered food, again related to the cycle of night and day and thus to feeding. During the night there is a transport and intra‐cellular digestion of zooxanthellae by amoebocytes from the mantle to the haemocoel surrounding the visceral mass. During the day digested zooxanthellae are transported to the digestive diverticula where they are discharged (together with the waste products of the intra‐cellular digestion of filtered food) into the tubule lumina and thus back into the stomach to be eventually voided via the anus. Recognizable zooxanthellae are also transported to the kidney, where they are taken up by the cells of the distal limb to form cellular globular concretions; these too are probably also eventually voided. The discharge of digested zooxanthellae via the digestive diverticula has resulted in modifications to the processes of tubule breakdown and reformation involving the digestive cells only. These unique modifications are described and compared with the structural changes seen in the digestive diverticula of other bivalves. It is concluded that the unusual functioning of the digestive diverticula is a direct consequence of the utilization by Tridacna of a secondary source of food without the concomitant evolution of special organs of digestion, as for example there has been in the Teredinidae feeding on filtered food and wood. Specific comparisons are made between the Tridacnidae and the Teredinidae and suggestions are made as to how zooxanthellae came to be used as food in these unusual bivalves.

show abstract

“…Mansour has also claimed direct connection between the cavity of the kidneys and of the visceral mass. The transverse sections that he photographs to illustrate the alleged opening (Mansour, 1946 b, fig. b ; 1946 c, P1.…”

Section: Mantle Chambers In the Tridacnidaementioning

confidence: 99%

Mantle chambers and water circulation in the Tridacnidae (Mollusca).

Yonge

1953

Proceedings of the Zoological Society of London

View full text Add to dashboard Cite

Source and Fate of the Zooxanthellæ of the Visceral Mass of Tridacna elongata

Cited by 18 publications

References 1 publication

Observations on the Symbiosis With Zooxanthellae Among the Tridacnidae (Mollusca, Bivalvia)

Observations on the Symbiosis With Zooxanthellae Among the Tridacnidae (Mollusca, Bivalvia)

The diurnal rhythm and the processes of feeding and digestion in Tridacna crocea (BivaMa: Tridacnidae)

Mantle chambers and water circulation in the Tridacnidae (Mollusca).

Contact Info

Product

Resources

About