Hardhead catfish, continued 



Range 



Overall : The range is along the Atlantic coast from 

 Cape Cod, Massachusetts to Yucatan, Mexico (Jones 

 et al. 1 978, Lee et al. 1 980). This species is extremely 

 abundant in the shallow coastal waters of North Caro- 

 lina, around Florida, and throughout the Gulf of Mexico, 

 but is absent from the Caribbean (Shipp 1986). 



Within Study Area : Within U.S. Gulf of Mexico estuar- 

 ies, hardhead catfish are found from the Rio Grande, 

 Texas, to Florida Bay, Florida. This is one of the most 

 ubiquitous fishes present in the brackish and salt 

 waters of the bays and shallow waters of the northern 

 Gulf of Mexico (Table 5.21) (Gunter 1945, Harris and 

 Rose 1968, Cornelius 1984). 



Life Mode 



Eggs and yolk sac larvae are carried in mouths of 

 males, but are demersal if dropped (Gunter 1947). 

 Juveniles and adults are demersal and predominantly 

 nocturnal (Darnell 1 958, Harris and Rose 1 968, Hoese 

 et al. 1968, Zimmerman 1969, Diener et al. 1974, 

 Dugas 1975, Steele 1984, Steele 1985, DeLancey 

 1989, Sogard et al. 1989) with some diurnal activity, 

 which can possibly be attributed to differences in life 

 cycle stages or seasonal variation (Hoese et al. 1 968, 

 Moore et al. 1 970). In areas of the Gulf of Mexico with 

 pronounced tidal fluctuations, activity associated with 

 high tides has been noted (Sogard et al. 1989). It is 

 often found in schools (Gunter 1938, Benson 1982) 

 which may be formed and maintained by specific 

 sounds it produces (Tavolga 1962). 



Habitat 



Ty pe: Eggs and yolk sac larvae are carried in the 

 mouths of adult males usually in shallow oligohaline to 

 mesohaline waters of bays, lagoons, or Gulf inlets (Lee 

 1937, Gunter 1947, Ward 1957, Zimmerman 1969, 

 Bechtel and Copeland 1970, Bryan 1971). Juveniles 

 are collected from fresh to euhaline salinities in waters 

 0.6 to 3.0 m in depth (Miller 1965, Swingle 1971, 

 Dunham 1972). They are apparently more numerous 

 than adults in waters of low salinity (Gunter 1947). 

 Adults are taken from fresh to hypersaline waters. 

 They have been collected at depths from 0.6 to 91 .4 m, 

 but principally from 4 to 7 m (Lee 1937, Gunter 1947, 

 Hildebrand 1954, Simmons 1957, Hoese 1960, Miller 

 1965, Perry 1970, Perret et al. 1971, Swingle 1971, 

 Dunham 1972, Franks et al. 1972, Swift et al. 1977, 

 Benson 1982, Cornelius 1984). They prefer warm 

 waters in shallow grassy areas of bays and the Gulf 

 (Lee 1937, Miles 1949, Hellier 1962, Miller 1965, 

 Zimmerman 1 969, Franks et al. 1 972, Chittenden and 

 McEachron 1976, Hoese and Moore 1977, Benson 

 1 982, Cornelius 1 984), but occasionally enter freshwa- 

 ter or brackish rivers and creeks (Swift et al. 1 977, Lee 

 et al. 1980, Loftus and Kushlan 1987). 



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