ALBERT

Description: Seven strains of five species of the genus Ectothiorhodospira were characterized by oligonucleotide cataloguing of their 16S rRNA in order to determine the phylogenetic relationship to one another and to other phototrophic purple bacteria. All representatives of Ectothiorhodospira are members of that line of descent defined by phototrophic purple sulfur bacteria and relatives, showing a moderate relationship to those phototrophic organisms forming globules of elemental sulfur inside the cell (Chromatium and relatives). The 5 Ectothiorhodospira species fall into two subgroups. E.halophila, E. halochloris and E. abdelmalekii form one, E. mobilis, E. shaposhnikovii and the unnamed strain BN 9906 form the second subgroup. Within the two subgroups the strains are closely related, while the degree of relatedness found between members of the two subgroups is more distant.

Description: The successful invasion of a non-native species depends on several factors, including initial colonization and establishment of a self-sustaining population. Populations of the non-native paddle crab Charybdis japonica were first recognized in the Waitemata Harbour, Auckland, New Zealand in 2000, most likely arriving in ballast waters of an Asian merchant vessel. A survey completed in 2003 found C. japonica throughout the Waitemata Harbour, and further sampling in 2009 has revealed several well established populations in estuaries up to 70 km from the putative invasion point. As the potential for further establishment of C. japonica beyond this area may depend on the temperature and salinity tolerances of their free swimming larvae, we quantified the survival of newly-hatched Stage 1 C. japonica zoeae subjected to temperatures ranging from 11 to 43°C or salinities from 5 to 45‰ in the laboratory. Upon hatching, replicate C. japonica zoeae were directly transferred from 21°C and 34.6‰ seawater to either an experimental temperature or salinity level. Behaviour and death rates of the larvae were monitored over a 24 h period in the absence of food. Comparisons of zoeal survival rates to historical sea surface temperatures and salinities show that C. japonica Stage 1 zoeae tolerate a broad range of temperatures and salinities and could survive natural conditions throughout New Zealand. This gives C. japonica the potential to invade many other New Zealand estuaries and harbours.

Description: The giant Australian cuttlefish Sepia apama Gray, 1849 annually forms a massive and unique spawning aggregation in northern Spencer Gulf, South Australia, which has attracted commercial fishing interests in recent years. However, many basic life-history characteristics of S. apama are unknown, and anecdotal evidence suggests that there is more than one species. The present study assessed the population structure and species status of S. apama using data from allozyme electrophoresis, microsatellite loci, nucleotide sequences of the mitochondrial COXIII gene, multivariate morphometrics and colour patterns. Analyses of allozyme and microsatellite allele frequencies revealed two very divergent but geographically separated populations consisting of specimens from the east coast and southern Australia. However, the presence of a heterozygote in a putative contact zone between the east coast and southern Australia suggested that these populations were not reproductively isolated. Mitochondrial haplotypes seem to have introgressed further north into the contact zone than have nuclear alleles. Differences in colour patterns that previously had been attributed anecdotally to different geographic populations were, in fact, correlated with sexual dimorphism. These data are most consistent with S. apama being one species the populations of which were geographically isolated in the past (historical vicariance) and have come into secondary contact. Comparison of microsatellite allele frequencies among four South Australian samples indicated significant deviations from panmixia. South Australian samples were also reliably diagnosed by means of multivariate morphometrics. Significant differences in mantle length were observed among populations.