We have determined the time course of the neuroendocrine response of Piebald-Viral-Glaxo (PVG) rats during the development of mycobacterially induced adjuvant arthritis. Anterior pituitary POMC mRNA increased at the time of onset of mycobacterially induced arthritis, but, paradoxically, coincident with the first signs of arthritis there was a consistent fall in CRF mRNA in the hypothalamic paraventricular nucleus. Coincident with this fall in CRF message, there was a corresponding decrease in CRF-41 peptide release into the hypophysial portal blood (HPB). In contrast, however, vasopressin release into the HPB was increased. There was an increase in adrenal weight associated with the development of arthritis, reflecting chronic activation of the HPA axis, which was reflected by increased circulating corticosterone concentrations. The synthetic adjuvant CP20961, which has different antigenic determinants, also caused an increase in POMC mRNA in the anterior pituitary, a decrease in CRF mRNA in the hypothalamic paraventricular nucleus, and a decrease in CRF-41 peptide release into the HPB in PVG rats 28 days after the induction of the arthritis. The arginine vasopressin level was not significantly different from the control value. In Sprague-Dawley rats, mycobacterial adjuvant resulted in a similar increase in POMC mRNA in the anterior pituitary 28 days after injection of the adjuvant. In this strain of rat there was no corresponding change in CRF mRNA. While there are some strain differences in the degree of change in CRF mRNA, both strains showed a common paradox of a marked increase in adenohypophyseal POMC mRNA not associated with increased CRF mRNA or peptide release. In the PVG strain of rat, CRF actually appears to be inhibited. The mechanisms involved in this disparity are unclear.

The whale shark is an ideal flagship species for 'citizen science' projects because of its charismatic nature, regular presence at numerous coastal aggregation sites and a growing number of ecotourism ventures focusing on the species. An online database of Whale Shark encounters, identifying individuals based on their unique skin patterning from 1992 to 2014 captured almost 30,000 whale shark encounter reports, comprising more than 6000 individuals identified from 54 countries. In this time the number of known whale shark aggregation sites increased from 13 to 20. Examination of encounters revealed a skewed sexratio bias towards males (overall >66%), high site fidelity amongst individuals with limited movements of sharks between neighbouring countries/regions but no records confirming 2 large, ocean basin-scale migrations. Citizen science has been vital in amassing large spatial and temporal datasets to elucidate key aspects of whale shark life-history and demographics and will continue to provide substantial long-term value.

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We made surveys for whale sharks Rhincodon typus on a total of 99 d from April through June each year from 2006 to 2008 along the southern fringe of the South Ari Atoll, Maldives Archipelago. We recorded the length and sex of each shark observed and made photographs to facilitate repeated identification from their spot patterns using pattern-recognition software. We identified 64 whale sharks from digital photographs taken during 220 sightings over 3 yr. Approx. 87% of those sharks were immature males. The average length of recognisable sharks was 5.98 m (range 2.5 to 10.5 m), significantly shorter than that reported for whale sharks in other aggregations in the Indian Ocean. Our findings suggest that these sharks are either a small proportion of a local population or perhaps an even smaller component of a regional population in the western Indian Ocean. We applied a Lincoln-Petersen closed-population mark-recapture model and a Jolly-Seber openpopulation model to estimate population size, but found that neither model provided reliable results because key assumptions of each were not met.

Adjuvant-induced arthritis results in chronic activation of the hypothalamo-pituitary-adrenal (HPA) axis. In the Piebald-Viral-Glaxo (PVG) rat, however, corticotropin-releasing factor (CRF) mRNA in the parvocellular paraventricular nucleus (pPVN) of the hypothalamus was reduced, and the normal corticosterone and CRF mRNA responses to acute stress were inhibited. The proenkephalin A mRNA response to stress in the pPVN was maintained, implying a specific inhibition of the CRF mRNA responses in this pathological situation. Adrenalectomy at day 0 (the time of adjuvant injection), day 13 (just before inflammation), or day 19 (submaximal inflammation) resulted in a marked increase in CRF mRNA compared with day 21 adrenal-intact arthritic animals. However, levels were below those of nonarthritic adrenalectomized rats, demonstrating that the inhibition of CRF mRNA associated with arthritis is not simply due to changes in glucocorticoid feedback. Proopiomelanocortin mRNA in the anterior pituitary was markedly increased in all adrenalectomized arthritic animals above the increase seen in sham-adrenalectomized day-21 arthritic rats. Adrenalectomy was always associated with an increase in the severity of the disease.

Whale sharks (Rhincodon typus) are an endangered species whose growth and reproductive biology are poorly understood. Given their conservation concern, estimating growth parameters, as traditionally derived from vertebral samples of dead animals, is challenging. We used a non-invasive approach to investigate growth parameters of whale sharks frequenting the South Ari Atoll, Maldives, by analysing repeat measurements of free-swimming sharks over a 10-year period. Total lengths of the sharks were estimated by three measurement methods. Visual estimates underestimated the sizes of large sharks, whereas laser and tape measurements yielded results that were similar to one another. The Maldives aggregation consisted of primarily male (91%) juvenile (total length=3.16–8.00m) sharks and sharks new to the area were significantly smaller than were returning sharks, which suggests that this site may constitute a secondary nursery ground. Estimates of von Bertalanffy (VBG) growth parameters for combined sexes (L∞=19.6m, k=0.021year–1) were calculated from 186 encounters with 44 sharks. For males, VBG parameters (L∞=18.1m, k=0.023year–1) were calculated from 177 encounters with 40 sharks and correspond to a male age at maturity of ~25 years and longevity of ~130 years. Differences between these estimates and those from other studies underscore the need for regional studies.

Whale sharks attract large numbers of tourists, divers and snorkelers each year to South Ari Atoll in the Republic of Maldives. Yet without information regarding the use and economic extent of the attraction, it is difficult to prioritize conservation or implement effective management plans. We used empirical recreational data and generalized mixed statistical models to conduct the first economic valuation (with direct spend as the primary proxy) of whale shark tourism in Maldives. We estimated that direct expenditures for whale shark focused tourism in the South Ari Marine Protected Area for 2012 and 2013 accounted for US$7.6 and $9.4 million respectively. These expenditures are based on an estimate of 72,000–78,000 tourists who are involved in whale shark excursions annually. That substantial amount of income to resort owners and operators, and tourism businesses in a relatively small area highlights the need to implement regulations and management that safeguard the sustainability of the industry through ensuring guest satisfaction and whale shark conservation.

The dorsal horn of the spinal cord, which forms the locus of first synapses in pain pathways, is an important site of interaction between calcitonin gene-related peptide (CGRP), substance P and enkephalin--the neuropeptides considered to be especially involved in the regulation of pain perception. Since adjuvant-induced arthritic rats provide a suitable model for peripheral inflammation and hyperalgesia, the possible alterations of immunoreactive CGRP, substance P and enkephalin as well as the binding sites for [125I]hCGRP alpha, [125I]substance P/neurokinin-1, (NK1) and [125I]FK-33-824/mu-opioid receptors were studied in the dorsal horn of the spinal cord receiving projections from the inflamed limbs. In arthritic rats compared to control animals, a bilateral increase in CGRP- and substance P-immunoreactive fibres and the presence of enkephalin-immunoreactive cell bodies were noted in the dorsal horn of the spinal cord. As for receptors, while a significant decrease in [125I]hCGRP alpha and [125I]substance P/NK1 binding sites was observed in selective layers, no measurable alteration in [125I]FK-33-824/mu-opioid binding sites was noted in any regions of the arthritic rat dorsal horn compared to the unaffected control rats. Following unilateral section of the peripheral nerve prior to induction of arthritis, CGRP- and substance P-immunoreactive fibres were markedly depleted and no enkephalin-positive neurons were observed in the ipsilateral dorsal horn. Analysis of receptor binding sites in denervated arthritic rats, however, exhibited differential responses, i.e. a significant increase in [125I]hCGRP alpha, a marked decrease in [125I]FK-33-824/mu-opioid and apparently no alteration in [125I]substance P/NK1 receptor binding sites were observed in the ipsilateral dorsal horn compared to the intact contralateral side. These results taken together provide anatomical evidence for a concerted role of these peptides in the regulation of adjuvant-induced hyperalgesia accompanying peripheral inflammation.