Jeotgalicoccus pinnipedialis sp nov., from a southern elephant seal (Mirounga leonina)

A previously unknown Gram-positive, catalase-positive, facultatively anaerobic, non-spore-forming, coccus-shaped bacterium (A/G14/99/10(T)), originating from the mouth of a female southern elephant seal, was subjected to a taxonomic analysis. Comparative 16S rRNA gene-sequencing showed that the organism formed a hitherto unknown subline within the catalase-positive, low-G+C, Gram-positive cocci, exhibiting a specific association with species of the genus Jeotgalicoccus. Sequence divergence values of approximately 7%, together with phenotypic differences, showed the unknown bacterium to be distinct from the two described species of this genus, Jeotgalicoccus halotolerans and Jeotgalicoccus psychrophilus. Based on phenotypic and phylogenetic considerations, it is proposed that strain A/G14/99/10(T)=CCUG 42722(T)=CIP 107946(T) from the mouth of a seal be classified as the type strain of a novel species of the genus Jeotgalicoccus, Jeotgalicoccus pinnipedialis sp. nov.

Facklamia miroungae sp. nov., from a juvenile southern elephant seal (Mirounga leonina)

An unusual gram-positive, catalase-negative, facultatively anaerobic, coccus-shaped organism that originated from a juvenile elephant seal was characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing showed that the unknown coccus represents a new subline within the genus Facklamia. The unknown strain was readily distinguishable from all currently recognized species of the genus Facklamia (Facklamia hominis, Facklamia languida, Facklamia ignava, Facklamia sourekii and Facklamia tabacinasalis) by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Facklamia miroungae sp. nov. The type strain of F. miroungae is CCUG 42728T (= CIP 106764T). F. miroungae is the first member of the genus Facklamia to be isolated from an animal other than man.

Variance in male reproductive success and sexual size dimorphism in pinnipeds: testing an assumption of sexual selection theory

The theory of evolution by sexual selection for sexual size dimorphism (SSD) postulates that SSD primarily reflects the adaptation of males and females to their different reproductive roles. For example, competition among males for access to females increases male body size because larger males are better able to maintain dominant status than smaller males. Larger dominant males sire most offspring while smaller subordinate males are unsuccessful, leading to skew in reproductive success. Therefore, species with male-biased SSD are predicted to have greater variance in male reproductive success than those in which both sexes are similar in size. We tested this prediction among the Pinnipedia, a mammalian group with a great variation in SSD. From a literature review, we identified genetic estimates of male reproductive success for 10 pinniped taxa (eight unique species and two subspecies of a ninth species) that range from seals with similarly sized males and females to species in which males are more than four times as large as females. We found no support for a positive relationship between variance in reproductive success and SSD among pinnipeds after excluding the elephant seals Mirounga leonina and Mirounga angustirostris, which we discuss as distinctive cases. Several explanations for these results are presented, including the revival of one of Darwin's original ideas. Darwin proposed that natural selection may explain SSD based on differences in energetic requirements between sexes and the potential for sexual niche segregation. Males may develop larger bodies to exploit resources that remain unavailable to females due to the energetic constraints imposed on female mammals by gestation and lactation. The importance of this alternative explanation remains to be tested.