Red drum, continued 



Mysidopsis almyra, are eaten by fish 1 to 1 69 mm TL, 

 but are most important in small juveniles 10 to 49 mm 

 TL, constituting 70 to 100% of their diet (Bass and 

 Avault 1 975, Peters and McMichael 1 987). Fish 30 mm 

 TL and over eat small crustaceans like schizopods and 

 amphipods (Darnell 1 958). Gammarid amphipods are 

 consistently found in 10-109 mm TL fish and are a 

 dominant food item in fish 30 to 60 mm TL (Bass and 

 Avault 1975, Peters and McMichael 1987). Generally, 

 at least five species of amphipods, including Ampelisca 

 sp. and Carinogammarius sp., are a minor part of the 

 diet, but are moderately important in fish 30 to 49 mm 

 TL. A large variety of decapods are eaten by fish 8 to 

 1 20 mm TL. The first to appear in the diet are caridean 

 shrimp, usually grass shrimp (Palaemonetes sp.), as 

 well as zostera shrimp (Hippolyte zostericola), bay 

 shrimp (Crangon sp.), and snapping shrimp (Alpheus 

 sp.). These are eaten until fish reach 150 to 159 mm 

 TL. Penaeid shrimp, including white shrimp, pink 

 shrimp, and brown shrimp, enter the diet offish 70 to 79 

 mm, and become important for fish 90 to 99 mm TL and 

 larger (Miles 1949, Bass and Avault 1975, Overstreet 

 and Heard 1 978, Peters and McMichael 1 987). Crabs, 

 though insignificant in the size classes from 30-69 mm 

 SL, begin to gain importance in juveniles >70 mm long 

 but remain secondary to shrimp (Morales and Dardeau 

 1987). At 100 to 175 mm TL, the chief food items are 

 small penaeid shrimp, palaemonetid shrimp, small 

 mullet, silversides, gobies, and small crabs (Simmons 

 and Breuer 1962, Morales and Dardeau 1987). Blue 

 crab and other portunid crabs are eaten by fish 40 to 49 

 mm TL, and are a common food item for fish 70 to 79 

 mm TL. Other crabs are found predominantly in larger 

 juveniles (>105 mmTL)and include fiddler crabs (Uca 

 sp.), heavy marsh crab (Sesarma reticulatum), mud 

 crabs, Eupagurus spp., and spidercrab (Libinia dubia), 

 but these are generally unimportant (Miles 1 949, Bass 

 and Avault 1 975, Peters and McMichael 1 987, Morales 

 and Dardeau 1987). Crabs predominate in the diet of 

 fish 1 84 to 625 mm TL, particularly blue crab and Harris 

 mud crab (Rhithropanopeus harrisii), and some fish as 

 well (Darnell 1958). Fish play a substantial role in the 

 diet of juveniles >1 5 mm TL, but were most abundant 

 in juveniles > 90 mm TL (Bass and Avault 1 975, Peters 

 and McMichael 1987). Juveniles 20 to 29 mm TL 

 began eating other sciaenids, usually spot, but also 

 some Atlantic croaker. Other fish consumed include: 

 speckled worm eel (Myrophis punctatus), gulf menha- 

 den, anchovies (Anchoa sp.), inshore lizardfish 

 (Synodus foetens), mullet, inland silverside (Menidia 

 beryllina), darter goby(Gobionellus boleosoma), and 

 bay whiff (Citharichthys spilopterus). 



Food habits vary little in fish 250 to 924 mm SL 

 (Boothby and Avault 1 971 ). Smaller fish generally eat 

 smaller sized items, but the three main groups, shrimp, 

 crabs, and fish, are eaten by all size classes. No 



noticeable difference has been observed between the 

 diets of males and females (Boothby and Avault 1 971 ). 

 Red drum 245 to 745 mm TL have been found to 

 consume algae, grass, eggs, cysts, detritus, mud and 

 sand, annelids, ostracods, amphipods, fish, penaeid 

 shrimp, and squid. Specific prey items include grass 

 shrimp, blue crab, mud crabs, bay shrimp (Crangon 

 sp.), estuarine ghost shrimp (Callianassajamaicense), 

 mullet, speckled worm eel {Myrophis punctatus), na- 

 ked goby (Gobiosoma bosci), sheepshead minnow, 

 gulf pipefish (Sygnathus scovelli), anchovies, menha- 

 den, hardhead catfish, rainwater killifish (Lucaniaparva), 

 spot, and blackcheektonguefish (Symphurus plagiusa) 

 (Pearson 1 928, Gunter 1 945, Knapp 1 949, Reid 1 955, 

 Reid et al. 1956, Simmons 1957, Breuer 1957, Bryan 

 1 971 , Diener et al. 1 974). Although crustaceans as a 

 group exceed fish in frequency of occurrence and per 

 cent volume of stomach contents, fish are consumed 

 more frequently, in greater numbers, and in greater 

 volume than shrimp or crabs alone. Plant and sub- 

 strate material that occurs in stomach contents are 

 probably taken incidentally during feeding activities. 

 Fish are generally more prevalent in the diet of red 

 drum during winter and spring months, menhaden 

 being a favorite. Crustaceans become increasingly 

 more important during late spring and by summer are 

 the main staple and continue as such until late fall. 

 Shrimp appear more frequently in stomach contents in 

 the spring, summer, and fall. Crabs are more frequent 

 than shrimp only in the winter (Boothby and Avault 

 1971). Other organisms eaten by juveniles contributed 

 little to stomach contents volume with the possible 

 exception of polychaetes, especially Glycera americana 

 (Bass and Avault 1975, Peters and McMichael 1987, 

 Morales and Dardeau 1 987). These were eaten by 30- 

 1 39 mm TL fish, but were most important to 60-79 mm 

 TL fish (Bass and Avault 1 975, Overstreet and Heard 

 1 978). Echinoderms are eaten regularly by large fish, 

 but are not an important diet item (Overstreet and 

 Heard 1978). Other species consumed in addition to 

 the main food species are: molluscs- Atlantic mud- 

 piddock (Barnea truncata), false angelwing (Petricola 

 pholodiformes), white baby-ear (Sinum perspectivum); 

 crustaceans- lesser blue crab (Callinectes simulis), 

 calico box crab (Hepatus epheliticus), lady crab 

 (Ovalipes ocellatus), longwrist hermit crab (Pagurus 

 longicarpus), iridescent swimming crab (Portunus 

 gibbesi), sea lice (Squilla sp.); echinoderms- Mellita 

 quinquiespen'orata, Sclerodactyla briareus; fishes- 

 striped killifish (Fundulus majalis), southern kingfish 

 (Menticirrhus americanus), pinfish, oyster toadfish 

 (Opsanus tau), Florida pompano, and hogchoker 

 {Thnectes maculatus) (Pearson 1928, Miles 1949, 

 Boothby and Avault 1 971 , Overstreet and Heard 1 978). 

 Bivalve molluscs, bivalve mollusc siphons, isopod crus- 

 taceans, and a marsh rat have also been reported from 

 stomach contents, but these items are not typical 



298 



