Phylogenetic relationships of the Antarctic euphausiids inhabiting the Ross Sea and the adjacent regions of Southern Ocean

• Published in: Cahiers de biologie marine Vol. 52; no. 1; pp. 1 - 11
• Main Authors: GIORDANO, Daniela, RINELLI, Paola, RUSSO, Aniello, SALA, Antonello, AZZALI, Massimo, LA SPADA, Gina, GIULIANO, Laura, CRISAFI, Ermanno, DE DOMENICO, Elena, YAKIMOV, Michail
• Format: Journal Article
• Language: English
• Published: Roscoff Ed. de la station biologique 01-03-2011
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Crustacea; Euphausia crystallorophias; Euphausia superba; Fundamental and applied biological sciences. Psychology; Invertebrates; Marine; Sea water ecosystems; Synecology; Antarctic Ocean; Ross Sea; PS, Ross Sea; PS, Antarctic Ocean; Euphausiacea; Genetic variability; Phylogenetic; Phylogeny; Euphausiids; Crustacea; Marine environment; Hydrobiology; Plankton; Arthropoda; Population; Ross Sea; Antarctica; Invertebrata
• ISSN: 0007-9723; 2262-3094

Ross Sea supports a large concentration of Antarctic krill (Euphausia superba Dana, 1850) and Ice krill (Euphausia crystallorophias Holt & Tattersal, 1906) that have a great ecological significance (Azzali & Kalinowski, 1999; Sala et al., 2002). The aim of this study was to further our understanding of the distribution and phylogeny of krill species that were collected in the Ross Sea during the XIX PNRA expedition. Krill from 33 net samples were examined by sequencing parts of two mitochondrial genes; 530 bp of the gene 16S from a total of 20 specimens and 983 bp of NADH from 200 specimens. BIO-ENV analysis showed that the distribution of these species correlated best with water temperature than bottom depth and the ice presence. AMOVA analysis, conducted using the NADH data among geographic populations, revealed no significant differences of nucleotide diversity within the two Euphausia species: E. superba (n = 100, h = 0.97533 plus or minus 0.0472, pi = 0.53433 plus or minus 0.17212), E. crystallorophias (n = 100, h = 0.81762 plus or minus 0.07431, pi = 0.48578 0.46825). contains as a subset ost of the variability is associated with individuals and may depend on the high polymorphism of the species. AMOVA analysis between net samples showed no significant differences in all species.Original Abstract: Relations phylogenetiques chez les Euphausides de la Mer de Ross et des regions adjacentes de l'Ocean Austral. La Mer de Ross abrite une grande concentration de krill antarctique (Euphausia superba Dana, 1850) et de krill de glace (Euphausia crystallorophias Holt & Tattersal, 1906) qui ont une grande importance ecologique (Azzali & Kalinowski, 1999; Sala et al., 2002). L'objectif de cette etude etait d'approfondir notre comprehension de la distribution et la phylogenie des especes de krill qui ont ete recueillis dans le la mer de Ross au cours de la XIXeme expedition PNRA . Des individus de 33 echantillons au filet ont ete examines par sequencage de portions de deux genes mitochondriaux; 530 pb du gene 16S sur un total de 20 individus et 938 pb de NADH sur 200 individus. Des analyses (BIO-ENV) ont montre que la distribution de ces especes est mieux correlee avec la temperature de l'eau qu'avec la profondeur ou la presence de glace. Des analyses moleculaires de variance (AMOVA) realisees a partir des donnees de NADH ne mettent pas en evidence de differences de diversite nucleotidique au sein de chaque espece: E. superba (n = 100, h = 0,97533 plus or minus 0,0472, pi = 0,53433 plus or minus 0,17212), E. crystallorophias (n = 100, h = 0,81762 plus or minus 0,07431, pi = 0,88567 plus or minus 0,46825). La plus grande part de la variabilite est associee au niveau individuel et peut dependre du polymorphisme eleve de l'espece. Les analyses AMOVA entre les echantillons n'ont montre aucune difference significative chez aucune espece.