Feeding Habits of Juvenile Lane Snapper Lutjanus synagris from Mississippi Coastal Waters, with Comments on the Diet of Gray Snapper Lutjanus griseus

Stomach contents analysis was used to quantitatively describe the diets of juvenile lane snapper, Lutjanus synagris, and juvenile gray snapper, Lutjanus griseus, from the northern Gulf of Mexico. Juvenile snapper were collected by trawling at two estuarine, deep channel sites in Mississippi coastal waters from September 1996 to January 1997. Lane snapper (n = 53) and gray snapper (n = 12) both consumed a variety of prey organisms, but primary prey were amphipods, decapods (shrimp and crabs), and fishes. The most important prey items for lane snapper based on percent Index of Relative Importance (%IRI) were shrimp remains (44%IRI), the shrimp Latreutes parvulus (23%IRI) and fish remains (13%IRI). Fishes of the genus Anchoa (43%IRI), shrimp remains (21%IRI) and the amphipod Corophium sp. (13%IRI) dominated the gray snapper diet. Intraspecific comparisons of lane snapper diet revealed significant overlap between collection sites, seasons and fish sizes

Diet of Tripletail, Lobotes surinamensis, from Mississippi Coastal Waters

The diet of tripletail, Lobotes surinamensis, collected from the Mississippi Sound and Mississippi\u27s offshore waters of the Gulf of Mexico between April and September 1995-1997, was investigated through analysis of stomach contents. Of 178 tripletail stomachs examined, 136 (76%) contained prey items, and 42 (24%) were empty. Tripletail with prey in their stomachs ranged from 183 to 787 mm total length (mean 522.6 mm) and 0.14 to 10.5 kg total weight (mean 3.64 kg). The diet consisted of 32 different prey types and was comprised of shrimp, crabs, and teleost fishes which were represented by about equal number and volume of prey but differed in relative importance to the diet, with fishes having greater importance. Principal contributors to the diet were Farfantepenaeus aztecus, Callinectes sapidus, Brevoortia patronus, and Chloroscombrus chrysurus. The variety of prey in the diet suggested that tripletail fed opportunistically

Habitat Condition and Associated Macrofauna Reflect Differences Between Protected and Exposed Seagrass Landscapes

Seagrass landscape configurations associated with different physical settings can affect habitat-structure and plant-animal relationships. We compared shoal grass (Halodule wrightii) habitat and macrofaunal variables between two fragmented seagrass landscapes at barrier-island locations subject to different disturbance regimes. Five seagrass habitat variables including above ground biomass (AGB), shoot number, per shoot biomass, epiphyte biomass and below ground biomass (BGB), differed significantly between the island landscapes. Per shoot biomass and epiphyte biomass also varied significantly over the seagrass growing season; and epiphyte biomass showed a strong landscape-time interaction. Abundances of microgastropods normalized to AGB differed significantly between landscapes. An inverse relationship between the abundance of microgastropods and epiphyte loading suggests a possible functional link. However, additional temporal mismatch between epiphyte loading and microgastropod abundance indicates that controls on epiphyte loading were complex. Seagrass habitat was more fragmented within the Cat Island (CI) landscape. Wind direction and strength imply that the CI landscape experienced more physical disturbance than the Horn Island (HI) landscape. This study highlights some potential links involving landscape configuration, habitat structure, and macrofaunal associations which can be further addressed using hypothesis-driven research

Trophic Relationships of Three Sunfishes (Lepomis spp.) in an Estuarine Bayou

We examined ontogenetic, interspecific, and seasonal trophic patterns among sympatric sunfish species, redspotted sunfish, Lepomis miniatus; redear sunfish; Lepomis microlophus; and bluegill, Lepomis macrochirus, in an estuarine bayou. In particular we studied these feeding patterns in relation to relative abundances of prey from different benthic feeding habitats. All three sunfishes showed ontogenetic divergence in their trophic niches, reflecting different ecomorphological specializations. Small fishes depended on zooplankton, whereas larger fishes of all three species shifted their diets to benthic macrofauna. A potential for trophic resource partitioning was reflected by dietary differences among the three sunfish species. One implied mechanism for resource partitioning was feeding habitat, as redear sunfish frequently used sediment-associated prey, while bluegill showed greater use of water-column-associated prey, and redspotted sunfish often used SAV-associated prey. However, all three sunfishes apparently used each feeding habitat to some degree; and, trophic differences were more clearly based on prey type than on feeding habitat. Redear sunfish, which can crush hard-shelled prey exhibited the most distinctive diet. An apparent seasonal shift in feeding habitat occurred in autumn/winter, as indicated by increased overlap between diets and SAV. This shift was facilitated by changes in the relative abundances of several common prey types between benthic habitats. The relative abundance and use of freshwater and estuarine-derived prey also varied seasonally, suggesting a possible trophic benefit of consistent prey availability in the estuarine bayou