Studies of the food habits of the fishes of the 

 Chenier Plain and adjacent coastal areas indicate that 

 spotted gar and bowfin are highly predacious. Food of 

 the very young consists almost entirely of small crus- 

 taceans and larval insects. Young bowfin, measuring 

 3.5 to 5.3 cm (1.4 to 2.1 in) in total lengtli, fed pre- 

 dominantly on cladocerans, amphipods and copepods 

 (50% of total volume) and to a lesser extent on iso- 

 pods, odonate naiads and adults, and diptera larvae at 

 Lacassine National Wildlife Refuge (Stacey et al. 

 1970). Similar results were reported from outside 

 Louisiana (Schneberger 1937, Pflieger 1975). No ref- 

 erences on food habits of young spotted gar in the 

 Chenier Plain are available, but Pflieger (1975) report- 

 ed that young spotted gar in Missouri ate foods simi- 

 lar to those eaten by young bowfin. As they grew old- 

 er, both species fed heavily on fishes and macrocrust- 

 aceans. 



Although the major diet of aduh bowfin from im- 

 pounded waters of the Chenier Plain is fish, grass 

 shrimp (Palaemonetes sp.) and crayfish {Procambams 

 sp.) are commonly eaten (Stacey et al. 1970). Bowfin 

 from the Atchafalaya Basin fed heavily on crayfish 

 throughout the year (primarily Procambams clarkii) 

 and to a lesser extent on fishes (Bryan et al. 1975). 

 Adult spotted gar are also reported to feed mostly on 

 fishes and macrocrustaceans. In nearby Atchafalaya 

 Bay, spotted gar fed heavily on Gulf menhaden (Hoese 

 1976), whereas in Lake Ponchartrain, blue crab, sun- 

 fishes, and shad were consumed (Lambou 1952, 

 Darnell 1958). In the Atchafalaya Basin, fishes made 

 up the majority of the spotted gar's diet, but a signi- 

 ficant amount (33% of food items) of crayfish was al- 

 so eaten (Bryan et al. 1975). 



Information is scarce about the spawning habits 

 of spotted gar and bowfin in coastal waters, but in the 

 Atchafalaya River Basin the major spawning season 

 apparently is from March to May. Bowfin may spawn 

 earlier in the year than most Basin fishes. Ripe 

 males and females were observed as early as January 

 when water temperatures were as low as 9°C. 



Ripe female spotted gar have been observed in the 

 Basin as early as March and as late as October. Suttkus 

 (1963) reported that spotted gar spawned during 

 April, May, and June in Lake Ponchartrain. Both spe- 

 cies spawned primarily in the quiet, sluggish waters of 

 interior bayous and swamps. 



Bowfin are nest-builders, and the males guard the 

 nest through the hatching period (Pflieger 1975). 

 Spotted gar apparently exhibit no parental care. Eggs 

 ofboth species are adhesive and adhere to any substra- 

 tum (Suttkus 1963, Pflieger 1975). Young bowfin, 

 measuring less than 10 cm (4 in) total length were ob- 

 served in schools in the Lacassine National Wildlife 

 Refuge in early April. Young bowfin take up a more 

 or less solitary existence after they exceed 10 cm 

 (4 in) in length. In Louisiana, young gar have been col- 

 lected from the Atchafalaya River and lower Missis- 

 sippi River drainages from AprO through June. Young 

 gar appear to be solitary individuals and show little in- 

 clination to school. Neither species exhibits much dai- 

 ly or seasonal movement. 



Salinity, turbidity, and current appear to be the 

 most significant factors affecting distribution of bow- 

 fin and spotted gar. Although spotted gar occur fre- 

 quently in large numbers in brackish waters there is no 

 evidence that the species spawn there. Bowfin show a 

 strong tendency to avoid salinities above 5%c and 

 neither it nor spotted gar frequent saltwater habitats. 



Turbid river channels, large lakes, and coastal bays 

 are apparently avoided by both species, but it is un- 

 clear whether current velocity, turbidity, or the lack 

 of cover is responsible. 



5.5.2 BLUE CATFISH {Ictalurus furcatus ) and 

 CHANNEL CATFISH (/. punctatus) 



The blue and channel catfishes are valuable sport 

 and commercial species that sometimes exceed 20 lbs 

 (9.1 kg) in weight. Channel catfish are extensively cul- 

 tured in ponds for U.S. markets. 



Blue catfish and channel catfish are native primar- 

 ily to the Mississippi River Basin and nearby coastal 

 waters and inhabit a wide variety of habitats ranging 

 from small ponds (when stocked) and clear flowing 

 streams, to large reservoirs and rivers. In Louisiana, 

 channel catfish tend to favor small to moderate-sized 

 bayous, canals, lakes, and rivers, whereas blue catfish 

 occur more frequently in large turbid riverine areas and 

 coastal bayous, lakes, and bays (Lantz 1970, Davis et 

 al. 1970, Juneau 1975, Hoese 1976, Tarver and Savoie 

 1976). Both species are most abundant in large bodies 

 of water such as the Mississippi and Red rivers, and the 

 Atchafalaya River Basin, and in interconnecting coast- 

 al lakes and bays. 



In the Chenier Plain area, blue catfish are more 

 abundant than channel catfish in brackish waters 

 (5%oj and less abundant in fresh waters (Darnell 1958, 

 Kelly 1965, Norden 1966, Fontenot and Rogillo 

 1970, Herke 1971, Adkins and Bowman 1976). 



In studies of relative abundance of fishes in the 

 Chenier Plain area, channel catfish were more abun- 

 dant than blue catfish in only two studies (Lantz 

 1970, Crandall et al. 1976); blue catfish predominated 

 in all others (Gunter and Shell 1958, Norden 1966, 

 Morton 1973, Perry 1967, 1976). Perry (1967) found 

 twice as many blue catfish as channel catfish in waters 

 surrounding Rockefeller Wildlife Refuge. Standing 

 crop estimates were 10.2 kg/ha (9.1 lb/a) for blue cat- 

 fish and 2.5 kg/ha (2.2 lb/a) for channel catfish (sali- 

 nities not given). The density of Texas Chenier Plain 

 populations of both species is apparenfly considerably 

 smaller than those in Louisiana (Reid 1956, Parker 

 1965, Crandall et al. 1976, Texas Parks and Wildlife 

 Department, unpublished reports). 



Both blue and channel catfishes are omnivorous 

 feeders throughout most of their lives. Young fish 

 feed on a diversity of items such as small crustaceans 

 and insects, living plant material, and organic detritus. 

 At Rockefeller Wildlife Refuge, Perry (1969) found 

 amphipods, diptera, filamentous algae, vascular plants, 

 and small fishes as major foods of young channel and 



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