First Record of a Nurse Shark, Ginglymostoma cirratum, within the Mississippi Sound

Of all the coastal shark species in the northern Gulf of Mexico, the nurse shark, Ginglymostoma cirratum, is one of the few species not documented in the Sound. Unlike most coastal sharks, nurse shark distribution is confined to a relatively specific suite of abiotic characteristics. Hannan et al. (2012) demonstrated that the distribution of nurse sharks in the northern GOM is primarily limited to hard bottom habitats with relatively high temperature, salinity, dissolved oxygen, and water clarity. Herein, we provide support for the findings of Hannan et al. (2012) and report the first documented occurrence of a nurse shark in the Sound

Investigating Life History Differences Between Finetooth Sharks, Carcharhinus isodon, in the Northern Gulf of Mexico and the Western North Atlantic Ocean

The life history of the finetooth shark, Carcharhinus isodon, off South Carolina was studied by determining age, growth, and size and age at maturity. These data were compared to a recent study describing the same parameters for finetooth sharks in the northern Gulf of Mexico. Cervical vertebrae were extracted from 168 specimens (71 males and 97 females), ranging in size from 376 to 1,262 mm fork length (FL), and prepared for age analysis using standard techniques. Sex-specific von Bertalanffy growth models were generated and yielded the following growth equations: Lt = 1,311 mm FL (1 - e-0.19(t - (-2.17))) for females and Lt = 1,151 mm FL (1 - e-0.33(t - (-1.43))) for males. The oldest female and male aged were 12.4 yr and 10.4 yr, respectively. Median length where 50% of the population was mature was 1,021 mm FL for females, corresponding to an age of 6.3 yr and 1,015 mm FL for males, corresponding to an age of 5.0 yr. Finetooth sharks in the western North Atlantic Ocean had higher observed ages and there was a significant difference in size at age between neonate finetooth sharks in the western North Atlantic Ocean and the northern Gulf of Mexico; however, there were no significant differences among von Bertalanffy growth function parameters between regions examined. Results indicate lower amounts of regional variation in life history parameters for finetooth sharks when compared to other small coastal sharks

Distribution and Length Frequency of Invasive Lionfish (Pterois sp.) in the Northern Gulf of Mexico

The purpose of this communication is to document continued spatial expansion of lionfish farther west into the northern Gulf of Mexico. Furthermore, we provide the first length— mass relationships and length frequency information for lionfishes captured within the northern GOM based on data collected as part of a broader on—going study of lionfish life history in this region

Observations of a Feeding Aggregation of Whale Sharks, Rhincodon typus, in the North Central Gulf of Mexico

On 26 June 2006 an aggregation of 16 whale sharks was observed for a period of 4 hr in the north central Gulf of Mexico (GOM). The sharks remained within an area about 1.0 km2 in size and continuously ram filter fed at the surface. Visual analysis of a plankton sample collected from the study site revealed the presence of copious amounts of fish eggs in mid-embryonic development and a minor amount of other zooplankton. A second plankton sample (control) collected about 3.5 km from the study site in an area where no whale sharks were present contained few eggs, however other zooplankton were similar to the study site sample in species composition and abundance. Two egg morphs were identified, and samples of one of the morphs, which represented 98% of the eggs at the study site, were verified by genetic analysis as little tunny, Euthynnus alleteratus. The observed feeding behavior and the abundance of fish eggs at the study site indicated the whale sharks were feeding on recently spawned little tunny eggs. This represents the first confirmed observation of a feeding aggregation of whale sharks in the GOM

Indication of Density-Dependent Changes in Growth and Maturity of the Barndoor Skate on Georges Bank

Drastic increases or decreases in biomass often result in density-dependent changes in life history characteristics within a fish population. Acknowledging this phenomenon and in light of the recent biomass increase in Barndoor Skate Dipturus laevis, the current study re-evaluated the growth rate and sexual maturity of 244 specimens collected from 2009-2011within closed areas I and II on Georges Bank, USA. Ages were estimated using vertebral band counts from skate that ranged from 21 to 129cm TL. The von Bertalanffy growth function was applied to pooled age-at-length data. Parameter estimates from the current study of L = 155cm TL and k = 0.10 represent a significant decrease from previously reported parameters of L = 167cm TL and k = 0.14. In addition to changes in growth parameters, age at 50% maturity for both males (based on clasper length, testes mass, and percent mature spermatocytes) and females (based on data from shell gland mass, ovary mass, and follicle diameter) increased by 3years and 4years, respectively. Based on our results and the 10- to 12-year gap in the collection of samples, it is likely that Barndoor Skate within this region have exhibited pliability in life history parameters

Notes on the Biology of an Adult Female Chimaera cubana Captured Off St. Croix, U.S. Virgin Islands

Within the western North Atlantic Ocean there are at least 4 genera and 5 species of chimaeroids occurring in deep waters generally associated with outer continental slopes or areas of high bathymetric relief (Didier 2002; Didier 2004). Two chimaeroids, Chimaera cubana and Hydrolagus alberti, are known to be indigenous to the Caribbean Sea in waters associated with the Greater and Lesser Antilles. While H. alberti occurs throughout the Gulf of Mexico and the Caribbean Sea, C. cubana is thought to be endemic to an area bounded by Cuba and Colombia (IUCN 2009). These two chimaeras are readily differentiated by the presence or absence of an anal fin and species–specific branching patterns of cranial lateral line canals (Didier 2004). Since the description of C. cubana by Howell–Rivero (1936), only 10 specimens have been reported in the primary literature with another 11 specimens located in museum collections (Bunkley–Williams and Williams 2004). The dearth of biological information on C. cubana led the International Union for the Conservation of Nature to recommend that “basic data be collected on all captures” (IUCN 2009)

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Variability in the Reproductive Cycle of Finetooth Sharks, \u3ci\u3eCarcharhinus isodon\u3c/i\u3e, in the Northern Gulf of Mexico

From 2005 through 2008, seven mature female Finetooth Sharks, Carcharhinus isodon, were collected in the central northern Gulf of Mexico between April and June, a time coinciding with parturition and ovulation for the species. Five specimens displayed states of pregnancy and ovarian development consistent with a biennial reproductive cycle. Two individuals had near-term pups and vitellogenic oocytes, a condition Indicative of an annual reproductive cycle. These observations are the first report of annual reproduction In Finetooth Sharks and represent the first documented case of intraspecific divergence in the reproductive cycles for any elasmobranch within a discrete area

Longevity of Atlantic Sharpnose Sharks Rhizoprionodon terraenovae and Blacknose Sharks Carcharhinus acronotus in the western North Atlantic Ocean based on tag-recapture data and direct age estimates [v2; ref status: indexed, http://f1000r.es/4fj]

Longevity of Rhizoprionodon terraenovae and Carcharhinus acronotus in the western North Atlantic Ocean was examined using direct age estimates from vertebral sections and tag-recapture data. Time-at-liberty ranged from 7.7-14.0 years (mean =10.1) for R. terraenovae and 10.9-12.8 years (mean =11.9) for C. acronotus. Maximum estimated longevity was determined to be 19.8 years through tag-recapture data and 18.5 years from direct age estimates for R. terraenovae and 22.8 years through tag-recapture data and 20.5 years through direct age estimates for C. acronotus. These longevity estimates represent a large increase over previous estimates and may have significant effects on analyses that depend on longevity including lifetime fecundity, mortality rates, demographic analyses and stock assessments