Mantle histology and histochemistry of three pearl oysters: Pinctada persica, Pinctada radiata and Pteria penguin

ABSTRACT

Shells in pearl oysters are produced by the mantle which is also used as a graft in pearl operations. Here, we investigate the mantle structure of a new pearl oyster species of the Persian Gulf, Pinctada persica, and compare it to two other pearl-producing species, Pinctada radiata and Pteria penguin. The anterior, ventral and posterior segments of the mantle edge of each valve were fixed, and tissue sections were stained with haematoxylin and eosin. A new pentachrome method and PAS-alcian blue staining were used to characterise the different mucosubstances. The mantle edges were found to have an outer, middle and inner fold, which have different morphology in each species. The mantle edge is lined by cuboidal and columnar epithelia, and interspersed among these epithelial cells we found mucous cells and cells that contained brown granules. The outer and middle folds of the two Pinctada species show different shapes to that of Pteria penguin. Most of the mucous cells in the mantle contain acidic mucosubstances and small amounts of mixed acidic-neutral mucosubstances were observed in the middle and inner fold of Pinctada persica. This study reveals that the mantle edges of the three species possess similar cellular structure, but vary in the shape of the folds.

KEYWORDS:

• Bivalve
• histology
• mantle
• mucosubstance
• Persian Gulf
• Pinctada persica

Acknowledgements

We thank Ms Laleh Daraei, the manager of SGP in Iran, also Dr Mohammad J. Shekarkhar, the authorised person of the Khalij Fars Hospital’s laboratory of Hormozgan Province, the fishermen of Berke-Khalaf village, Qeshm Island and Professor Hamid R. Esmaeeli, University of Shiraz, who provided the necessary facilities to develop this study. We also thank Dr Masahiko Awaji, Dr Kevin Doello, Dr Narges Amrollahi, Dr Ali A. Hedayati, Mr Amir Qadermarzi and Dr Carmel McDougall for providing valuable guidance towards improving the manuscript. All individual rights, animal rights and scientific ethics have been observed in this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was financially supported by UNDP-GEF/SGP Iran [IRA-06-04 (71 st)].