to note the habitat for the frogs. Brown (1950) re- 

 corded an individual specimen from south of Beau- 

 mont, Texas, but listed no habitat information. 

 These frogs are fairly common in many freshwater 

 ponds, streams, and marshes within the Chenier Plain, 

 but detailed studies of niche parameters and responses 

 to habitat fluctuations are warranted and essential for 

 future management of Chenier Plain populations. 



Extensive literature exists on the foods and feed- 

 ing habits of bullfrogs. Among the more detailed re- 

 ports are those of Needham 1905;Wriglit 1914, 1920; 

 Frost 1935; Wright and Wright 1949; Ryan 1953; 

 Gentry 1955; Korschgen and Moyle 1955; Smith 

 1956; Cohen and Howard 1958; Smith 1961; Korsch- 

 gen and Baskett 1963; Brooks 1964; Reggio 1967; 

 Stokes 1967; Schroeder and Baskett 1968; Mueller 

 1969; Taylor and Michael 1971; Stewart and Sandi- 

 son 1972; Collins 1974; Mount 1975. 



Mount(1975)commented: 'The bullfrog is a vor- 

 acious feeder, capturing and swallowing abiiost any- 

 thing of appropriate size that crosses its path. Inverte- 

 brates constitute the bulk of the diet, but birds, 

 snakes, turtles, mice, and other frogs, including mem- 

 bers of its own species, may also be included.' Insects 

 and crustaceans are the major invertebrates consumed 

 according to Smith (1961). 



Published papers about food habits of Chenier 

 Plain bullfrogs are not known, but future investigators 

 would do well to examine the papers of Reggio 

 (1967), Taylor and Michael (1971), and unpublished 

 studies by D. D. CuUey, Jr. of Louisiana State Univer- 

 sity. 



Apparently no published studies exist on the re- 

 productive requirements of bullfrog populations on 

 the Chenier Plain. 



The quality, depth, and duration of standing and 

 moving waters must be of prime consideration in de- 

 veloping a bullfrog management program. The rela- 

 tionships of submergent and emergent vegetation, 

 ground cover and shoreline cover, bottom quality, 

 water temperature variation and the chronology of 

 this variation, seasonal variability in presence and 

 availability of dissolved gases, and water salinities to 

 the various Ufe history stages of bullfrogs must be 

 studied in detail. The effects of periodic invasions of 

 saltwater by hurricanes must be determined. Food 

 availability must be at suitable levels and variety for 

 early and late larvae and post-metamorphic stages. 

 Chemical pollution of habitat waters must be avoided. 

 Most pesticides, herbicides, defoliants, etc., should 

 never be utilized near sites where bullfrogs are abun- 

 dant. 



Excessive predation, particularly hunting by hu- 

 mans, can be damaging. Keiser (1976a) noted that 

 adult frogs in the Atchafalaya Basin are easy to cap- 

 ture in the spring when water hyacinths are not abun- 

 dant, and that buUfrogging at such times may be re- 

 sponsible for the drastic reductions in local popula- 

 tions. He reported that most spawning occurred dur- 

 ing the month of June and recommended that Louisi- 

 ana's frogging season be closed from early March 



through June 15, in order to reestablish or increase 

 bullfrog populations in areas where they are depleted. 

 Other activities of humans are often detrimental, e.g., 

 dredging, deforestation, and removal of brush along 

 stream banks and lake borders. 



Certain color phases of adult bullfrogs resemble 

 those of adult pig frogs (Rana grylio) and these two 

 species are often confused. Both are large, edible frogs 

 and are common within their respective Chenier Plain 

 habitats, though pronounced habitat differences 

 should be evident when studies become available. Dif- 

 ferences in the two species are discussed by Stejneger 

 (1901), Wright and Wright (1949), Dundee (1974), and 

 Keiser (1976a). 



5.5.1 



5.5 FINFISHES 



SPOTTED GAR (Lepisosteus oculatus) and 

 BOWFIN (Amia calva) 



Spotted gar and bowfin are predatory freshwater 

 species that have little sport or commercial value, de- 

 spite their availabUity to sport and commercial gear. 

 Individuals exceeding 1 .8 kg (5 lb) in weight are com- 

 mon. Fishery management has been directed toward 

 destroying these species because of their reputation 

 for competing with sport fish for space and food and 

 because of their predatory habits. 



These two freshwater fishes are relatively com- 

 mon in the coastal wetlands and freshwater tributaries 

 ofmuchof the Gulf of Mexico. In southern Louisiana, 

 the gar and bowfin are found largely in rivers, bayous, 

 small lakes, canals, estuaries, and impoundments. They 

 usually avoid fast-flowing waters. Because of their air- 

 breathing capabilities, both species may survive in 

 oxygen-depleted waters for relatively long periods of 

 time, but in severely depleted waters high mortality 

 may occur (Bryan et al. 1976). 



Spotted gar are listed as common and bowfin as 

 rare in low-salinity bayous and marshes of western 

 Chenier Plain (Parker 1965). Of the two species, the 

 spotted gar has a greater tendency to inhabit brackish 

 waters (5%o) in the Chenier Plain (Kelly 1965, 

 Parker 1965, Norden 1966,Herke 1971,Hoese 1976, 

 Perry 1976). 



In the more eastern areas of the Chenier Plain, 

 near Lacassine and Sabine National Wildlife refuges, 

 both species are abundant and comprise a significant 

 part of the standing-crop biomass of fishes (Turner 

 1966). Trawling studies in Grand and White lakes and 

 nearby coastal bays indicated that both species were 

 rare at the time, while studies in adjacent brackish 

 marshes showed that spotted gar are often very abun- 

 dant (Gunter and Shell 1958, Norden 1966, Herke 

 1971, Morton 1973, Perry 1976). Fish populations 

 studies in the brackish waters of Rockefeller Wildlife 

 Refuge revealed a standing crop of 14.2 kg/ha (12.6 

 lb/a) for spotted gar and less than 1 kg/ha (0.89 lb/a) 

 for bowfin (Perry 1976). In impounded waters of the 

 Texas Chenier Plain, standing-crop estimates of both 

 species were much higher; 180 kg/ha (161 lb/a) for 

 spotted gar and 160 kg/ha (143 lb/a) for bowfin 

 (Crandall et al. 1976). 



252 



