Gross Brain Morphology in the Yellow Stingray, Urobatis jamaicensis

The yellow stingray, Urobatis jamaicensis (family Urolophidae), a short-lived, relatively small elasmobranch species (35--40 cm total length), is a common inhabitant of hard bottom and coral reef communities in southeastern Florida and many parts of the Caribbean. A paucity of published studies deal with the yellow stingray, none however on the gross morphology of its nervous system. The gross brain structure of the yellow stingray is compared with previously published studies on other batoid elasmobranchs. The external brain structure of Urobatis jamaicensis was similar to that reported for other Dasyatids, including presence of an asymmetric cerebellum. The bilaterally symmetric brain is well developed and quite large in proportion to body size (≈1--2% bw). Stingrays generally possess a brain three to 10 times the size of their sister groups, the electric rays, guitarfish, and skates (Northcutt, 1989), the yellow stingray is no exception

Tires: Unstable Materials For Artificial Reef Construction

Artificial reefs of varied materials have been deployed worldwide to acquire large and diverse fish assemblages for both commercial and sport fishers, and SCUBA divers. Beginning in 1967, environmental resource managers and local fishers initiated a project to build an artificial reef using banded, but unballasted, waste automobile and truck tires offshore Broward County, Florida, USA. Estimates of the number of tires placed offshore range between 1,000,000– 2,000,000. Since deployment, storm events and ocean currents have caused the bands to give way and the break-up of the reef. Over the years, many tires have washed ashore onto recreational beach areas. Tires that remain in the water continue to move with wave action and currents. Many of these remaining tires have already been forced up against the offshore edge of natural reef with numbers at individual sites estimated in the 100,000\u27s. The objectives of this project were to examine the feasibility of removing the tires as well as gain subjective insight into the impact of the tires on natural habitat. Sixteen hundred tires were removed from the reef edge and recycled. The potential problems arising from the use of tires in artificial reef construction were apparent. Natural reef fauna was broken and buried providing a seascape resembling a junkyard. The shortsighted use of unstable material to construct artificial reefs is an issue facing many coastal areas. Disturbance of this unstable material has futher added to other natural and anthropogenic stresses suffered by the coral reef systems and the wildlife they support. Clearly, unstable materials, such as tires, are not suitable for artificial reef construction. If already deployed, tires should be removed to prevent physical damage to the natural habitat and reduce the related negative biological impacts, in turn, limiting economic loss to local communities benefiting from use of the natural reef. Keywords: southeast Florida, recycling, habitat restoration

Site-Dependent Differences in Artificial Reef Function: Implications for Coral Reef Restoration

There is an increasing use of artificial structure in coral reef restoration (for references, see Spieler et al., this volume). Often artificial reef structures are chosen for a restoration project simply because they were used elsewhere. However, it is questionable whether the results obtained at one restoration site can be extrapolated to another. In recent years, several studies have examined the effect of artificial reef site selection on formation of associated fish, algae, and/or invertebrate assemblages (Alevizon et al., 1985; Blinova et al., 1994; Bombace et al., 1994; Caley and St. John, 1996; Chang, 1985; Haughton and Aiken, 1989; Hixon and Beets, 1989; Jara and Cespedes, 1994; Kruer and Causey, 1992; Lozano-Alvarez et al., 1994; Moffitt et al., 1989; Relini et al., 1994; Sherman et al., 2000; Sherman et al., 1999; Sogard, 1989; Spieler, 1998; Tomascik, 1991). Although not designed specifically as coral reef restoration projects, the results of these studies lend insight into the problems of restoration. This paper is an overview of recent literature on site selection intended for resource managers interested in using artificial reefs in coral reef restoration. To that end, we re-examined the data from several studies comparing similar artificial reef structures at different sites

Artificial Substrate and Coral Reef Restoration: What Do We Need to Know to Know What We Need

To use artificial substrate effectively in coral reef restoration certain basic knowledge is required: (1) what is the artificial substrate expected to accomplish relative to the goals of the restoration effort and (2) what are the expected interactions of the selected substrate’s composition, texture, orientation, and design with the damaged environment and the biota of interest. Whereas the first point is usually clear, at least in general terms, the second is not. In this review, we examine: the functions of artificial substrate in restoration and some of the physical (i.e., composition; surface texture; color and chemistry; and design in terms of profile, shelter, shading, size and configuration, settlement attractants, and stability) and environmental factors (i.e., temperature, light sedimentation, surround biota, hydrodynamics, depth, and temporal effects) affecting these functions. We conclude that until substantial additional research is accomplished, the use of artificial substrate in coral reef restoration will remain a ‘best guess’ endeavor. Areas requiring additional research are identified and some potentially promising lines of inquiry are suggested

Development of Embryonic Gill Vasculature in the Yellow Stingray, Urobatis jamaicensis

Corrosion casting was utilized to examine the development of gill vasculature in embryonic yellow stingrays, Urobatis jamaicensis (formerly Urolophus jamaicensis). The most marked changes in vascular configuration of the gills occur in the earliest castable stages of gestation. These changes included development of afferent external gill filament vessels and progression from paired dorsal aortae to a single fused dorsal aorta. Internal gill vasculature was found to nearly match that of an adult by the time the external gill filaments had fully regressed and yolk sac had been exhausted (\u3e47 mm disc width). Examination of embryo casts also revealed characteristics of the branchial vasculature not previously reported in adult specimens. These include the presence of pre-lamellar sphincters, intertrematic branches, afferent distributing arteries, which supply blood to many afferent filament arteries resulting in greater interconnection of the filaments, and observation that the afferent branchial artery in the first hemibranch supplies blood directly to afferent filament arteries on the dorsal half of this arch

The Yellow Stingray, Urobatis jamaicensis (Chondrichthyes Urotrygonidae): A Synoptic Review

The yellow stingray, Urobatis jamaicensis (Cuvier) has been the subject of a multitude of diverse studies on its natural history, morphology, and physiology. We have attempted here to briefly review all the studies on U. jamaicensis both published and unpublished with the goal of providing comparative information for researchers working on related species as well as to highlight areas of research requiring further investigation in this one

Presence of Juvenile Blackfin Snapper, Lutjanus buccanella, and Snowy Grouper, Epinephelus niveatus, on Shallow-water Artificial Reefs

The inshore environment of Broward County, Florida consists of three reef tracts, each separated by sand substrate, running parallel to the coastline in sequentially deeper water. A wide variety of artificial reef designs have been deployed in Broward County, many lying in sand flats between the reeftracts. From 1995 through 2002, over 1,100 visual fish censuses (predominantly point-counts) were completed on the three natural reeftracts in water depths from 3 m to 30 m and over 1,100 censuses were done on artificial reefs at depths of 7 m to 23 m. Curiously, the juvenile stages of two deeper-water species of the snapper/grouper complex, the blackfin snapper (Lutjanus buccanella) and the snowy grouper (Epinephelus niveatus), appear to prefer artificial reefs located in the sand flat separating the second and third reeftracts to nearby natural reef areas. Five hundred and forty blackfin snapper have been recorded in 64 visual censuses and nine snowy grouper have been observed in seven counts on artificial reefs. Despite the large volume of visual census data collected thus far, these two species have never been recorded on nearby natural reef tracts. The reasons for this unanticipated observation is unclear but it provides an excellent launch-point for an examination of juvenile habitat requirements, natural availability of these requirements, and the potential for artificial substrate to be used in managing these species