Determining the geographic scale at which to apply ecosystem-based management (EBM) has proven to be an obstacle for many marine conservation programs. Generalizations based on geographic proximity, taxonomy, or life history characteristics provide little predictive power in determining overall patterns of connectivity, and therefore offer little in terms of delineating boundaries for marine spatial management areas. Here, we provide a case study of 27 taxonomically and ecologically diverse species (including reef fishes, marine mammals, gastropods, echinoderms, cnidarians, crustaceans, and an elasmobranch) that reveal four concordant barriers to dispersal within the Hawaiian Archipelago which are not detected in single-species exemplar studies. We contend that this multispecies approach to determine concordant patterns of connectivity is an objective and logical way in which to define the minimum number of management units and that EBM in the Hawaiian Archipelago requires at least five spatially managed regions.

Lacto-N-fucopentaose III (LNFPIII) is found in human milk and on the Th2 driving helminth parasite Schistosoma mansoni. This pentasaccharide drives Th2-type responses in vivo and in vitro when conjugated to a carrier. In an attempt to further understand early events in Th1 to Th2 switching, we examined phenotypic and functional changes in peritoneal cell populations in BALB/c and SCID mice following LNFPIII-dextran injection. We found that i.p. injection with LNFPIII-dextran resulted in rapid (<20 h) expansion of the Gr1+ subpopulation of F4/80+/CD11b+ peritoneal cells, comprising up to 75% of F4/80+/CD11b+ peritoneal cells compared with 18% in uninjected or dextran-injected mice. Functionally, these cells suppressed anti-CD3- and anti-CD28-induced proliferation of naive CD4+ T cells. LNFPIII-dextran also expanded functional Gr1+ suppressor macrophages in SCID mice, demonstrating that expansion and function of suppressor cells did not require T cells. Suppression in both BALB/c and SCID mice was NO and IFN-γ dependent, as addition of inhibitors of inducible NO synthase (NG-monomethyl-l-arginine), as well as anti-IFN-γ Abs, restored the ability of CD4+ T cells to proliferate in vitro. Depletion of the F4/80+ subset of Gr1+ cells eliminated the suppressive activity of peritoneal exudate cells showing that these cells were macrophages. Thus, LNFPIII-dextran rapidly expands the Gr1+ suppressor macrophage population in the peritoneal cavities of otherwise naive mice. These Gr1+ cells suppress proliferation of naive CD4+ T cells in an NO-dependent mechanism, and may play a regulatory role in the switching of Th1- to Th2-type responses.

BackgroundThe scalloped hammerhead shark, Sphyrna lewini, is a large endangered predator with a circumglobal distribution, observed in the open ocean but linked ontogenetically to coastal embayments for parturition and juvenile development. A previous survey of maternal (mtDNA) markers demonstrated strong genetic partitioning overall (global ΦST = 0.749) and significant population separations across oceans and between discontinuous continental coastlines.Methodology/Principal FindingsWe surveyed the same global range with increased sample coverage (N = 403) and 13 microsatellite loci to assess the male contribution to dispersal and population structure. Biparentally inherited microsatellites reveal low or absent genetic structure across ocean basins and global genetic differentiation (F ST = 0.035) over an order of magnitude lower than the corresponding measures for maternal mtDNA lineages (ΦST = 0.749). Nuclear allelic richness and heterozygosity are high throughout the Indo-Pacific, while genetic structure is low. In contrast, allelic diversity is low while population structure is higher for populations at the ends of the range in the West Atlantic and East Pacific.Conclusions/SignificanceThese data are consistent with the proposed Indo-Pacific center of origin for S. lewini, and indicate that females are philopatric or adhere to coastal habitats while males facilitate gene flow across oceanic expanses. This study includes the largest sampling effort and the most molecular loci ever used to survey the complete range of a large oceanic predator, and findings emphasize the importance of incorporating mixed-marker analysis into stock assessments of threatened and endangered shark species.

Proposed benefits of multiple paternity include increased reproductive output, elevated fitness of progeny, and maintenance of population genetic diversity. However, another consideration is whether multiple paternity is simply an unavoidable byproduct of sexual conflict, with males seeking to maximize mating encounters while females seek to minimize the stress of copulation. Here we examined the polyandrous mating system in sharks, with a focus on the reproductive genetics of the shortspine spurdog Squalus mitsukurii. Members of the genus Squalus are long-lived, slow-growing, and employ among the longest gestation periods of any vertebrate. To evaluate multiple paternity and genetic diversity in S. mitsukurii, we genotyped 27 litters plus 96 individuals with 8 microsatellite loci. Further, 670 bp of the mtDNA control region were sequenced in 112 individuals to examine population structure. S. mitsukurii in Hawaii showed low genetic diversity relative to other sharks (π = 0.0010 ± 0.0008) and no significant population structure in the Hawaiian Archipelago. Direct allele counts and Bayesian approximations returned concordant estimates of 11% multiple paternity, the lowest observed in sharks to date. Considering the protracted reproductive interval of S. mitsukurii, sexual conflict that results from differential male and female reproductive strategies may favor the development of female mating avoidance behavior to minimize trauma. In S. mitsukurii this behavior includes segregation of sexes and an asynchronous reproductive cycle.KEY WORDS: Elasmobranch · Polyandry · Control region · Microsatellite DNA · Population structure · Sexual conflict · Sexual segregation · Reproductive strategy Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 403: [255][256][257][258][259][260][261][262][263][264][265][266][267] 2010 females with conventional sex roles (reviewed by Zeh & Zeh 2003). Polyandry (females mating with more than one male) and multiple paternity (a single brood of offspring sired by multiple males) are now recognized as common strategies in widely divergent taxa including amphibians, mammals, reptiles, insects, crustaceans, and fishes (Evans & Magurran 2000, Toonen 2004, Adams et al. 2005, Bretman & Tregenza 2005, Daly-Engel et al. 2006, Dean et al. 2006, Jensen et al. 2006. It is still unclear, however, what roles sexual conflict and intersexual selection might play in polyandrous mating systems.For males, the advantages to having multiple breeding partners are clear: the more females a male inseminates, the more offspring he fathers and the greater his reproductive fitness. The benefits of polyandry to females are less obvious. Potential direct benefits to the female include nuptial gifts or parental care on the part of the male. No direct benefits have been shown in shark mating systems, though there is potential for indirect or genetic benefits through polyandrous mating. If there is little or no opportunity to evaluate males prior to copulation, a f...

This review highlights the potential role that post‐copulatory sexual selection plays in elasmobranch reproductive systems and the utility of this group to further understanding of evolutionary responses to the post‐copulatory processes of sperm competition and cryptic female choice. The growing genetic evidence for female multiple mating (polyandry) in elasmobranchs is summarized. While polyandry appears to be common in this group, rates of multiple paternity are highly variable between species suggesting that there is large variance in the strength of post‐copulatory sexual selection among elasmobranchs. Possible adaptations of traits important for post‐copulatory sexual selection are then considered. Particular emphasis is devoted to explore the potential for sperm competition and cryptic female choice to influence the evolution of testes size, sperm morphology, genital morphology and sperm storage organs. Finally, it is argued that future work should take advantage of the wealth of information on these reproductive traits already available in elasmobranchs to gain a better understanding of how post‐copulatory sexual selection operates in this group.