1 Laboratory of Aquaculture and Bioremediation, Faculty of Nature and Life Sciences, University Oran1-Ahmed Ben Bella P.B. 1524 El M'Naouer 31000 Oran, Algeria;
2 Faculty of Nature and Life Sciences, University of Sciences and Technology- Mohamed Boudiaf, El Mnaouar BP 1505, Bir El Djir 31000, Oran, Algeria;
3 Ecophysiologie et Métabolisme des Microalgues (EA 2150, Mer, Molécules, Santé), Facutlé des Sciences et Techniques, Université du Maine, Av. O. Messiaen, 72085 Le Mans Cedex 9, France;
4 Ifremer, IRD, CNRS, Univ. Nouvelle Calédonie, Univ. la Réunion, UMR 9220 ENTROPIE, 101 Promenade Roger Laroque, 98897 Noumea, New Caledonia;
5 Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, 70-383 Szczecin, Poland.
Contacts: mustapha.benkada@outlook.com and thierry.jauffrais @ ifremer.fr
This work describes sev eral Hasleataxa isolated from New Caledonia marine waters.The genus Haslea is one among many genera of pennate diatoms belonging to Naviculaceae. The most famous species of the genus is its type species, Haslea ostrearia (Gaillon) Simonsen. This blue pigmented diatom, colored by marennine in vacuoles at cell apices,has long been known for being responsible for a desirable green colourin oysters. Greening of oysters, at an economic scale, is mainly practiced on the AtlanticCoast of France, giving an added value to the bivalves. Currently, the genus Haslea encompasses ca. 40 species, which present significant differences in morphology, ecology, and pigment composition. Our knowledge about the biodiversity of blue Haslea species has recently increased with the discovery of 3 new species producing marennine-like blue pigments. Our work presents preliminary results about the diversity of Haslea spp. isolated from Padina sp. growing in coral reef habitats and from aquaculture earth pounds used for shrimp cultures. After isolation of single cells, clonal cultures were carried out under controlled conditions using ES1/3 and L1 media. After light microscopy observations, the strains were identified and characterized using SEM pictures. Different information were retrieved, the characteristic bilayered cell wall with longitudinal strips of silica at the external valve surface and the quadrate areolae at internal valve surface, the raphe shape, the stria density, foramen shape and cell size. These results were coupled to molecular analysis using markers rbcL cox 1 and 18SrDNA to confirm their systematic position.
Keywords: Bacillariophyta, Haslea, Marennine, SEM, taxonomy, New Caledonia
