Preventing behavioural interactions with a male facilitates sex change in female bluebanded gobies, Lythrypnus dalli

Sex change in marine teleost fishes is commonly regulated by social factors. In species that exhibit protogynous sex change, such as the bluebanded goby Lythrypnus dalli, the most dominant female typically initiates sex change when a male is removed from the social group. Females can use visual, chemical or tactile cues to assess the presence or absence of a male. The primary goal of our study was to determine whether the olfactory and visual presence of a male versus its behavioural interactions with females were important for mediating sex change. We exposed females to three different treatments: absence of a male, presence of a male that could physically interact with her and presence of a male behind a barrier that allowed visual and olfactory interactions but prohibited physical interactions. Sex change occurred in the absence of a male but not in the presence of a male that could physically interact with the female. The presence of a male behind the barrier did not prevent sex change but affected the timing of sex change. Season appeared to affect the latency to initiate male typical courtship, with a delay at the end of the reproductive season only when the male was present behind the barrier. We discuss the seasonal results in terms of L. dalli life history and the potential benefits and costs of changing sex late in the season in the presence or absence of aggressive reinforcement by the male. Our results identify direct behavioural interactions as an important proximate mechanism in the social regulation of sex change in L. dalli.     

The oil and gas sector: from climate laggard to climate leader?

ABSTRACT

The oil and gas industry has traditionally been reticent to engage with the issues surrounding climate change, typically being cast as a laggard. Yet, over recent years, the sector has begun taking on a more active role in climate governance, doing so in a variety of capacities – as initiators, catalysts and participants in industry-led or multi-stakeholder efforts. The Oil and Gas Climate Initiative is reviewed, as a case study to illustrate emerging climate leadership within the global oil and gas industry. In 2015, its members committed to a two-degree pathway. The paucity of research on the nascent role of oil and gas firms in climate governance is addressed.     

STATE WATER PLANNING: A FORUM FOR PROACTWELY RESOLVING WATER POLICY DISPUTES1

ABSTRACT: In the arid West, the development and implementation of water policy often results in disputes among water users, resource managers, and policy makers. Although significant attempts have been made to improve public involvement and dispute resolution in water resources planning, the traditional planning process has not historically played this role for a variety of reasons. Water resources planning can become a forum for proactively resolving water policy disputes by employing the principles of environmental dispute resolution. The purpose of this article is to explore the role of collaborative, consensus-building planning processes in resolving water policy disputes. The Montana State Water Plan is evaluated as an example of such a process, and a model state water planning process is outlined.     

Three-spined stickleback: an emerging model in environmental endocrine disruption.

The three-spined stickleback, a small teleost species with habitats that range from full marine to fresh water bodies across the whole Northern hemisphere, has a number of advantages for endocrine disruption research. It is the only teleost species with an unambiguous biomarker for androgens, the presence of the glue protein spiggin in the male kidney, which can be measured by enzyme-linked immunosorbent assay (ELISA). The androgen assay has been adopted to detect antiandrogens in two different ways and an homologous ELISA for stickleback vitellogenin is also available. DNA markers for molecular sex determination are available; thus, sex ratios can also be used for in situ biomonitoring. In addition, the critical period of sexual differentiation has been determined and the occurrence of intersex fish has been reported several times. The species full genome sequence is almost complete. All aspects of stickleback biology (ecology, evolution, behavior, physiology, endocrinology) are well documented. In European waters, the stickleback is the only fish that can bring laboratory and field studies together and allow the true impact of endocrine disruptors on fish populations to be evaluated.     

Cuticular hydrocarbons and reproductive status in the social wasp Polistes dominulus

Most species of social insect are characterized by a reproductive division of labor among morphologically specialized individuals. In contrast, there exist many species where all individuals are morphologically identical and dominance relationships determine which individuals mate and/or reproduce. In newly founded multiple-foundress associations of the social wasp Polistes dominulus, foundresses establish dominance hierarchies where the top-ranked (alpha) female monopolizes egg laying. The possibility that chemical cues are used for recognition of egg-laying individuals has not been explored in this wasp. Using non-destructive techniques, we examined the relationship between ovarian activity and the proportions of cuticular hydrocarbons of three female types (dominant and subordinate foundresses and workers) in 11 colonies. Immediately after nest foundation, no differences were found between alpha and subordinate females. In contrast, at worker emergence, alpha females were statistically distinguishable from both subordinates and workers. We experimentally removed the alpha female in 5 of the original nests and reanalyzed hydrocarbon proportions of the new dominant individual. Replacement individuals were all found to acquire a cuticular signature characteristic of the alpha female. This suggests that cuticular hydrocarbons are used as cues of ovarian activity in P. dominulus, and we discuss our results in terms of a switch from behavioral dominance to chemical signaling in this wasp.