scholarly journals What causedG. truncatulinoidesto calcify in shallower water during the early Holocene in the western Atlantic / Gulf of Mexico?

2010 ◽  
Vol 9 ◽  
pp. 012020 ◽  
Author(s):  
Caroline Cléroux ◽  
Jean Lynch-Stieglitz
Keyword(s):  
Gulf Of Mexico ◽  
Early Holocene ◽  
Western Atlantic

Gonad morphology and gametogenesis in the deep-sea jellyfish Atolla wyvillei and Periphylla periphylla (Scyphozoa: Coronatae) collected from Cape Hatteras and the Gulf of Mexico

2009 ◽  
Vol 90 (6) ◽  
pp. 1095-1104 ◽  
Author(s):  
Cathy H. Lucas ◽  
Adam J. Reed
Keyword(s):  
Gulf Of Mexico ◽  
Gonad Development ◽  
Bell Diameter ◽  
Western Atlantic ◽  
Gonad Morphology ◽  
Time Period ◽  
Cape Hatteras ◽  
Literature Evidence ◽  
Long Time ◽  
North Western

Observations on gonad morphology and the structure of ovaries and testes of the coronate scyphozoans Atolla wyvillei and Periphylla periphylla are described based on samples collected from the Gulf of Mexico and Cape Hatteras (north-western Atlantic). In A. wyvillei, gonads of distinguishable sex were observed in medusae as small as 17 mm bell diameter (BD). Spermatogenesis occurred within follicles (average 366 × 254 μm) that were evenly distributed throughout the gonad. Oocytes in different stages of development were observed in all the females with gonads. Oocytes arise from the gastrodermis and migrate into the mesoglea to develop from early-mid to late vitellogenic oocytes characterized by a large nucleus and granular (organic-rich) cytoplasm. The largest oocytes measured were 543 μm and 263 μm from the Gulf of Mexico and Cape Hatteras respectively. Possible reasons for this difference are discussed. In P. periphylla gonads were also initially observed in medusae 17 mm BD, although not all larger medusae had obvious gonads. Unlike A. wyvillei sperm follicles were arranged in long convoluted rows normally only one follicle thick. The organization of ooytes in female P. periphylla was very similar to A. wyvillei, although the gonads were small and the number of oocytes present in each gonad very low (<22). The largest oocyte measured was 777 μm in a 53 mm BD medusa. Although medusae were collected from one time period only (September) in this study, our findings appear to be in agreement with literature evidence indicating that coronate jellyfish produce few eggs continuously over a long time period. Aspects of gonad development and gametogenesis are discussed with respect to potential differences in site productivity and species identification.

Coenobichnus currani (new ichnogenus and ichnospecies): Fossil trackway of a land hermit crab, early Holocene, San Salvador, Bahamas

2003 ◽  
Vol 77 (3) ◽  
pp. 576-582 ◽  
Author(s):  
Sally E. Walker ◽  
Steven M. Holland ◽  
Lisa Gardiner
Keyword(s):  
Hermit Crab ◽  
Fossil Record ◽  
Trace Fossil ◽  
Early Holocene ◽  
Hermit Crabs ◽  
Coastal Environments ◽  
Atlantic Region ◽  
Western Atlantic ◽  
San Salvador ◽  
Left And Right

Land hermit crabs (Coenobitidae) are widespread and abundant in Recent tropical and subtropical coastal environments, yet little is known about their fossil record. A walking trace, attributed to a land hermit crab, is described herein as Coenobichnus currani (new ichnogenus and ichnospecies). This trace fossil occurs in an early Holocene eolianite deposit on the island of San Salvador, Bahamas. The fossil trackway retains the distinctive right and left asymmetry and interior drag trace that are diagnostic of modern land hermit crab walking traces. The overall size, dimensions and shape of the fossil trackway are similar to those produced by the modem land hermit crab, Coenobita clypeatus, which occurs in the tropical western Atlantic region. The trackway was compared to other arthropod traces, but it was found to be distinct among the arthropod traces described from dune or other environments. The new ichnogenus Coenobichnus is proposed to accommodate the asymmetry of the trackway demarcated by left and right tracks. The new ichnospecies Coenobichnus currani is proposed to accommodate the form of the proposed Coenobichnus that has a shell drag trace.

Age and growth of the great hammerhead shark, Sphyrna mokarran, in the north-western Atlantic Ocean and Gulf of Mexico

2010 ◽  
Vol 61 (9) ◽  
pp. 992 ◽  
Author(s):  
Andrew N. Piercy ◽  
John K. Carlson ◽  
Michelle S. Passerotti
Keyword(s):  
Atlantic Ocean ◽  
Gulf Of Mexico ◽  
Biological Data ◽  
Age And Growth ◽  
Von Bertalanffy ◽  
Western Atlantic ◽  
K Value ◽  
Hammerhead Shark ◽  
Western Atlantic Ocean ◽  
North Western

The great hammerhead shark, Sphyrna mokarran, is a cosmopolitan species that is caught in a variety of fisheries throughout much of its range. The apparent decline of great hammerhead shark populations has reinforced the need for accurate biological data to enhance fishery management plans. To this end, age and growth estimates for the great hammerhead were determined from sharks (n = 216) ranging in size from 54- to 315-cm fork length (FL), captured in the Gulf of Mexico and north-western Atlantic Ocean. Growth curves were fitted using multiple models and evaluated using Akaike’s information criterion. The von Bertalanffy growth model was the best fitting model, with resulting growth parameters of L∞ = 264.2-cm FL, k = 0.16 year–1, t0 = –1.99 year for males, and L∞ = 307.8-cm FL, k = 0.11 year–1, t0 = –2.86 year for females. Annual band pair deposition was confirmed through marginal-increment analysis and a concurrent bomb radiocarbon validation study. Great hammerheads have one of the oldest reported ages for any elasmobranch (44 years) but grow at relatively similar rates (on the basis of von Bertalanffy k value) to other large hammerhead species from this region. The present study is the first to provide vertebral ages for great hammerheads.

MORBILLIVIRUS INFECTION IN BOTTLENOSE DOLPHINS: EVIDENCE FOR RECURRENT EPIZOOTICS IN THE WESTERN ATLANTIC AND GULF OF MEXICO

2006 ◽  
Vol 12 (4) ◽  
pp. 499-515 ◽  
Author(s):  
Pádraig J. Duignan ◽  
Carol House ◽  
Daniel K. Odell ◽  
Randall S. Wells ◽  
Larry J. Hansen ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Bottlenose Dolphins ◽  
Western Atlantic

scholarly journals Predicting the effects of climate change on bluefin tuna (Thunnus thynnus) spawning habitat in the Gulf of Mexico

2011 ◽  
Vol 68 (6) ◽  
pp. 1051-1062 ◽  
Author(s):  
Barbara A. Muhling ◽  
Sang-Ki Lee ◽  
John T. Lamkin ◽  
Yanyun Liu
Keyword(s):  
Climate Change ◽  
Gulf Of Mexico ◽  
Climate Model ◽  
Bluefin Tuna ◽  
Spawning Ground ◽  
Thunnus Thynnus ◽  
Spawning Habitat ◽  
Western Atlantic ◽  
Model Simulations ◽  
Climate Model Simulations

Abstract Muhling, B. A., Lee, S-K., Lamkin, J. T., and Liu, Y. 2011. Predicting the effects of climate change on bluefin tuna (Thunnus thynnus) spawning habitat in the Gulf of Mexico. – ICES Journal of Marine Science, 68: 1051–1062. Atlantic bluefin tuna (BFT) is a highly migratory species that feeds in cold waters in the North Atlantic, but migrates to tropical seas to spawn. Global climate-model simulations forced by future greenhouse warming project that upper-ocean temperatures in the main western Atlantic spawning ground, the Gulf of Mexico (GOM), will increase substantially, potentially altering the temporal and spatial extent of BFT spawning activity. In this study, an ensemble of 20 climate model simulations used in the Intergovernmental Panel for Climate Change fourth Assessment Report (IPCC-AR4) predicted mean temperature changes within the GOM under scenario A1B through to 2100. Associations between adult and larval BFT in the GOM and sea temperatures were defined using 20th century observations, and potential effects of warming on the suitability of the GOM as a spawning ground were quantified. Areas in the GOM with high probabilities of larval occurrence decreased in late spring by 39–61% by 2050 and 93–96% by the end of the 21st century. Conversely, early spring may become more suitable for spawning. BFT are therefore likely to be vulnerable to climate change, and there is potential for significant impacts on spawning and migration behaviours.

scholarly journals A new species of the remarkable brittle star genus Astrophiura (Echinodermata: Ophiuroidea) from the western Atlantic Ocean

Zootaxa ◽  
2018 ◽  
Vol 4378 (2) ◽  
pp. 257 ◽  
Author(s):  
DAVID L. PAWSON
Keyword(s):  
New Species ◽  
Atlantic Ocean ◽  
Gulf Of Mexico ◽  
Dorsal Surface ◽  
Western Atlantic ◽  
Disc Diameter ◽  
Southern Caribbean ◽  
Bright Orange ◽  
A New Species

Astrophiura caroleae, new species, is described from off Curacao in the southern Caribbean, and from the western Gulf of Mexico, in depths of 244 to 434 meters. This new species, the first in the genus Astrophiura to be described from the Atlantic Ocean, has a distinctive combination of characters, including regularly arranged primary plates, large radial shields whose radial edges are in contact for their entire visible length, and prominent tubercles on central and radial plates. The mottled reddish coloration of the dorsal surface of this species usually contrasts with the color of the substratum, rendering it readily visible in situ, despite its disc diameter of less than 10 mm. Like its congeners, A. caroleae is gonochoric, the gonads of females containing conspicuous masses of bright orange eggs that are approximately 165 µm in diameter. DNA Barcoding data are provided for this new species, these are the first for Astrophiura. 

scholarly journals Setting the record straight on invasive lionfish control: Culling works

2014 ◽  
Author(s):  
Isabelle M Côté ◽  
Lad Akins ◽  
Elizabeth Underwood ◽  
Jocelyn Curtis-Quick ◽  
Stephanie J Green
Keyword(s):  
Coral Reefs ◽  
Gulf Of Mexico ◽  
Prey Fish ◽  
Western Atlantic ◽  
Behavioural Changes ◽  
Invasive Lionfish ◽  
Per Se ◽  
Reef Fauna

Indo-Pacific lionfish have invaded large parts of the western Atlantic, Caribbean and Gulf of Mexico, and have already caused measurable declines in native Atlantic reef fauna. Culling efforts are occurring across the region, particularly on coral reefs, to reduce local lionfish abundances. Frequent culling has recently been shown to cause a shift towards more wary and reclusive behaviour by lionfish, which has prompted calls for halting culls. However, the effectiveness of culling per se is not in question. Culling successfully lowers lionfish numbers and has been shown to stabilise or even reverse declines in native prey fish. In fact, partial culling is often as effective as complete local eradication, yet requires significantly less time and effort. Abandoning culling altogether would therefore be seriously misguided and a hindrance to conservation. We offer suggestions for how to design removal programs that minimize behavioural changes and maximize culling success.

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