Preliminary Results Regarding Isolation Of Blue And Non-blue Haslea spp. From New Caledonia (Southwest Pacific)M. Mohamed-Benkada 1,2, J.-L. Mouget 3, M. B. Baba Hamed 1, D. Ansquer 4, N. Callac 4, R. Gastineau 5, A. Witkowski 5, T. Jauffrais 4

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: and thierry.jauffrais @


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