13 research outputs found
Composition of the Ichthyofauna Inhabiting the 110-Meter Contour of the Gulf of Mexico, Mississippi River to the Rio Grande
The ichthyofauna inhabiting the 110-m bathymetric contour from the Mississippi River to the Rio Grande was very diverse in comparison to the inshore fauna, although the number of species collected decreased off south Texas. A total of 69 species were identified, although only 3662 specimens were examined. Dominant taxa were the families Sparidae, Lutjanidae, Triglidae, Serranidae and Synodontidae with Stenotomus caprinus, Pristipomoides aquilonaris, Prionotus paralatus, Serranus atrobranchus, and Synodus joetens being the most abundant species. Faunal composition was very similar along the entire 110-m contour except for large changes in abundance of Stenotomus caprinus, Pristipomoides aquilonaris, and Serranus atrobranchus. Abundance of Stenotomus caprinus decreased greatly off south Texas whereas the converse was true for Pristipomoides aquilonaris and Serranus atrobranchus. The composition of the ichthyofauna at a depth of 110-m is similar to that found on the brown shrimp grounds of the northern Gulf of Mexico
Seasonal Occurrence of Black Drum, Pogonias cromis, and Red Drum, Sciaenops ocellatus, Off Texas
Age, Growth, and Mortality of Atlantic Croaker, Micropogonias undulatus, in the Chesapeake Bay Region, With a Discussion of Apparent Geographic Changes in Population Dynamics
Atlantic croaker, Micropogonias undulatus, collected from commercial catches in Chesapeake Bay and in Virginia and North Carolina coastal waters during 1988-1991 (n=1,967) were aged from transverse otolith sections. Ages 1-8 were recorded, but eight-year-old fish were rare. Marginal increment analysis showed that for ages 1-7, annuli are formed once a year during the period April-May. Otolith age readings were precise: \u3e99% agreement within and between readers. Observed lengths-at-age were highly variable and growth rate decreased after the first year. Despite the high variability in sizes-at-age, observed lengths for ages 1-7 fit the von Bertalanffy growth model (r2=0.99; n=753) well. No differences in growth were found between sexes. Total annual instantaneous mortality (Z) estimated from maximum age and from a catch curve of Chesapeake Bay commercial catches ranged from 0.55 to 0.63. Our results do not indicate the existence of a group of larger, older Atlantic croaker in Chesapeake Bay compared with more southern waters and suggest that the hypothesis of a basically different population dynamics pattern for this species north and south of Cape Hatteras, North Carolina, should be reevaluated
Spatial and Temporal Occurrence of Spanish Mackerel Scomberomorus maculatus in Chesapeake Bay
Sharp Reductions in Abundance of Fishes and Benthic Macroinvertebrates in the Gulf of Mexico Off Texas Associated with Hypoxia
Food Habits of the Rock Sea Bass, Centropristis philadelphica, in the Western Gulf of Mexico
The rock sea bass, Centropristis philadelphica, is a euryphagic, benthic carnivore. Principal prey in decreasing order of importance are: natantian and reptantian decapods, mysids, fishes, stomatopods and polychaetes. As rock sea bass increase in size, crabs and fishes constitute a greater portion of their diet and mysids a smaller portion. Feeding activity is greater during daytime though diurnal dietary compositions are similar. Shrimps are the principal food in every season but are more notable during fall and winter than spring and summer; mysids and crabs are most important in spring, as are fishes in summer. Inshore (\u3c 27 m deep) the primary foods are shrimps, mysids, larval fish and stomatopods; offshore, crabs and fishes dominate the diet. The euryphagic feeding of rock sea bass is similar to other small, co-occurring serranids, and morphologically they fit the description of a benthic forager in convergence of body form. The ability of rock sea bass to utilize temporal-spatially abundant prey probably facilitates their broad bathymetric distribution (4-120 m) and relatively high abundance in the western Gulf of Mexico
PDE 7 Inhibitors: New Potential Drugs for the Therapy of Spinal Cord Injury
BACKGROUND: Primary traumatic mechanical injury to the spinal cord (SCI) causes the death of a number of neurons that to date can neither be recovered nor regenerated. During the last years our group has been involved in the design, synthesis and evaluation of PDE7 inhibitors as new innovative drugs for several neurological disorders. Our working hypothesis is based on two different facts. Firstly, neuroinflammation is modulated by cAMP levels, thus the key role for phosphodiesterases (PDEs), which hydrolyze cAMP, is undoubtedly demonstrated. On the other hand, PDE7 is expressed simultaneously on leukocytes and on the brain, highlighting the potential crucial role of PDE7 as drug target for neuroinflammation. METHODOLOGY/PRINCIPAL FINDINGS: Here we present two chemically diverse families of PDE7 inhibitors, designed using computational techniques such as virtual screening and neuronal networks. We report their biological profile and their efficacy in an experimental SCI model induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. We have selected two candidates, namely S14 and VP1.15, as PDE7 inhibitors. These compounds increase cAMP production both in macrophage and neuronal cell lines. Regarding drug-like properties, compounds were able to cross the blood brain barrier using parallel artificial membranes (PAMPA) methodology. SCI in mice resulted in severe trauma characterized by edema, neutrophil infiltration, and production of a range of inflammatory mediators, tissue damage, and apoptosis. Treatment of the mice with S14 and VP1.15, two PDE7 inhibitors, significantly reduced the degree of spinal cord inflammation, tissue injury (histological score), and TNF-α, IL-6, COX-2 and iNOS expression. CONCLUSIONS/SIGNIFICANCE: All these data together led us to propose PDE7 inhibitors, and specifically S14 and VP1.15, as potential drug candidates to be further studied for the treatment of SCI