(DRAFT) - Taxonomy
                                Species catfish, sea
                                 Species Id M010080
                                   Date 27 AUG 96



TAXONOMY

NAME - catfish, sea OTHER COMMON NAMES - Smallmouth catfish, silver catfish, hardhead and tourist trout ELEMENT CODE - CATEGORY - Fish PHYLUM AND SUBPHYLUM - Chordata, CLASS AND SUBCLASS - Osteichthyes, ORDER AND SUBORDER - Siluriformes, FAMILY AND SUBFAMILY - Ariidae, GENUS AND SUBGENUS - Arius, SPECIES AND SSP - felis, SCIENTIFIC NAME - Arius felis AUTHORITY - Linnaeus TAXONOMY REFERENCES - 79 COMMENTS ON TAXONOMY - Naked skin, large serrated spines located at the front of the dorsal and pectoral fins, adipose fins, and a forked caudal fin are marine catfish features common with freshwater catfishes (Ictalurus). No barbels on nostrils, steel blue-gray dorsally, and silvery sides are distinctive marine catfish features. The sea catfish has two pain of short rounded barbels on lower chin, maxillary barbels nearly as long as the head. Dorsal and pectoral fins without first rays elongated separate sea catfish from gafftopsail catfish with elongated first rays. Body is elongated, steel-blue above and silvery below.*79* Taxonomy - 1
                                  (DRAFT) - Status
                                Species catfish, sea
                                 Species Id M010080
                                   Date 27 AUG 96



STATUS

Coded Status See Comments REFERENCES FOR STATUS - 79 COMMENTS ON STATUS - Sea catfish are not favored sport or food fishes; however, their widespread distribution and abundance along the nearshore coast from southern Florida to western Texas cause them to rank high in trawl and saltwater angler catches in the Gulf of Mexico. Angler surveys along the northern gulf coast ranked sea catfish harvest ususally 2nd or 3rd and no lower than 13th among all saltwater finfishes. Industrial and commerical catches of this fish are purposefully low because area with high abundance are avoided unless suitable higher valued fishes co-exist. Catfish are usually culled from trawl catches because of low consumer acceptance in pet food products or as human food fish.*79* Status - 1
                               (DRAFT) - Distribution
                                Species catfish, sea
                                 Species Id M010080
                                   Date 27 AUG 96



DISTRIBUTION

Distribution - 1
     

HABITAT ASSOCIATIONS

Habitat Associations - 1
                                (DRAFT) - Food Habits
                                Species catfish, sea
                                 Species Id M010080
                                   Date 27 AUG 96



FOOD HABITS

TROPHIC LEVEL - OMNIVORE REFERENCES FOR TROPHIC LEVEL - 79 LIFESTAGE FOOD FOOD PART General Cnidaria Not Specified General Polychaetes Not Specified General Snails Not Specified General Crustaceans Not Specified General Algae Not Specified Juvenile Microorganisms Not Specified REFERENCES FOR GENERAL FOOD - 79 REFERENCES FOR JUVENILE FOOD - 79 COMMENTS ON FOOD - Algae, sea grasses, coelentrates, holothurians, gastropods, polychates, crustaceans (shrimp and crabs), and fishes were common items in stomachs of sea catfish. Large fish scales and human garbage indicated scavenging. It was reported that sea catfish concentrated at a hot-water discharge to feed on discharged impinged prey organisms and small blue crabs when the water temperature remained below 38 degrees C.*79* COMMENTS ON ADULT FOOD - It was found that adult sea catfish eat 44% organic detritus, 34% large invertebrates, and 21% microinvertebrates.*79* COMMENTS ON JUVENILE FOOD - Juvenile sea catfish have been reported to feed on microcrustaceans while still being carried in males' mouths. It was reported that larger juvenile sea catfish stomachs contained 56% organic detritus, 26% microinvertebrates, and 16% larger invertebrates.*79* Food Habits - 1
                         (DRAFT) - Environment Associations
                                Species catfish, sea
                                 Species Id M010080
                                   Date 27 AUG 96



ENVIRONMENTAL ASSOCIATIONS

G = General A = Adult LIM = Limiting RA = Resting Adult J = Juvenile FA = Feeding Adult RJ = Resting Juvenile BA = Breeding Adult FJ = Feeding Juvenile P = Pupae L = Larvae E = Egg RL = Resting Larvae FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS A Water Temperature: Between 21-27 degrees C A Water Temperature: Specified in Comments J Water Temperature: Specified in Comments A L J J REFERENCES FOR ENVIRONMENTAL ASSOC_ - 79 REFERENCES FOR ADULT ENVIRONMENTAL ASSOC_ - 79 REFERENCES FOR JUVENILE ENVIRONMENTAL ASSOC_ - 79 REFERENCES FOR LARVAE ENVIRONMENTAL ASSOC_ - 79 COMMENTS ON ENVIRONMENTAL ASSOCIATIONS - Depth preference of sea catfish appears to be related to water temperatures and bottom composition. They begin moving offshore or into warmer waters associated with deep channels as water temperatures drop below 10 to 15 degrees C in late fall only to return in spring when water temperatures rise above these levels. Higher abundances in shallow inshore coastal areas and estuaries appear related to organic substrate and associated invertebrate food sources. The low frequency of catfish in small seine samples suggests they do not commonly occur in shoreline beach habitats.*79* Water Movement Water movements appear to be used by ariid catfishes to locate and obtain prey. Spawning and oral gestations occurred in shallower bay areas where water movements are reduced.*79* Turbidity Sea catfish tend to be found in turbid, shallow, coastal waters with sand or mud substrate. There is a preference for inshore muddy or sandy bottoms of high organic content. Sounds produced by these fish could enable catfish to avoid obstructions, and probably predators, at close range. Sounds also enable catfish to communicate with each other during breeding and nocturnal schooling. Sea catfish produce "percolator" choruses from Environment Associations - 1 (DRAFT) - Environment Associations Species catfish, sea Species Id M010080 Date 27 AUG 96 1700 to 2250 during April through October. A summer lull occurs in July and August when light intensity falls below 1900 fc. Sound orientation and communication, along with highly developed olfactory senses, would be especially useful in turbid waters.*79* COMMENTS ON ADULT ENVIRONMENTAL ASSOC_ - Temperature Adult sea catfish prefer water temperatures above 25 degrees C, but avoid waters over 37 degrees C. Sea catfish were collected from 38 to 39 degrees effluent but some fish were observed in apparent thermal shock. They leave inshore areas for deeper channels or offshore areas when water temperatures drop below 5 to 6 degrees C.*79* Salinity Adult sea catfish have been captured from waters with salinities ranging from 0 to 40 ppt.*79* COMMENTS ON BREEDING ADULT ENVIRONMENTAL ASSOC_ - Spawning and oral gestation occurred in shallower bay areas where water movements are reduced.*79* COMMENTS ON JUVENILE ENVIRONMENTAL ASSOC_ - Juveniles were collected in 16.7 to 28.3 ppt salinities. Juveniles have also been found in water with 0.1 ppt salinity. Juveniles are reported to be more numerous than adults in low salinity waters.*79* COMMENTS ON RESTING JUVENILE ENVIRONMENTAL ASSOC_ - Juveniles, independent of parents, tend to be found in quiet water bays.*79* COMMENTS ON RESTING LARVAE ENVIRONMENTAL ASSOC_ - Yolk-sac larvae were found in the mouths of males in water salinities 8.3 to 12.8 ppt.*79* Environment Associations - 2
                               (DRAFT) - Life History
                                Species catfish, sea
                                 Species Id M010080
                                   Date 27 AUG 96



LIFE HISTORY

Morphology Naked skin, large serrated spines located at the front of the dorsal and pectoral fins, adipose fins, and a forked caudal fin are marine catfish features common with freshwater catfishes (Ictalurus). No barbels on nostrils, steel blue-gray dorsally, and silvery sides are distinctive marine catfish features. The sea catfish has two pain of short rounded barbels on lower chin, maxillary barbels nearly as long as the head. Dorsal and pectoral fins without first rays elongated separate sea catfish from gafftopsail catfish with elongated first rays. Body is elongated, steel-blue above and silvery below.*79* Spawning Sea catfish reach sexual maturity before 2 years of age. Sea catfish spawn from May to August in back bays sometimes as shallow as 0.6 to 1.2 m (2 to 4 ft) with salinities from 13 to 30 ppt. Females develop flaplike, adipose tissue on pelvic fins and pelvic fins of females of are larger than pelvic fins of males. It was speculated that the highly adhesive nature of extruded eggs from sea catfish and the highly modified pelvic fin flaps suggested fertilization on and transfer from the female's pelvic fins to the male's mouth. The eggs might be picked up from sandy depressions since eggs of these two ariid catfish are demersal and early stages (gastrula) are not reported in collections from males' mouth. Female sea catfish from the Mississippi Sound contained 6 to 8 mm eggs in April, 9 to 14 mm eggs in May, and 14 to 16 mm eggs in June and July. Ova in females during early June enlarged by the addition of yolk and became greenish shortly before ovulation. Male sea catfish contained motile sperm from March until mid-July. Males carried developing young in their mouths from early May until early August.*79* Fecundity and Eggs The large eggs (14 to 19 mm in diameter) and parental care by males offset the low fecundities of 20 to 64 eggs per female. Smaller, nonfunctional hyaline eggs, attached opposite the micropyle of larger extruded eggs, may serve as a nutritional source for the males during the 60 to 80-day oral gestation period. Sea catfish eggs are 12 to 19 mm in diameter, greenish, and demersal; fertilized eggs are oval or elliptical shaped and 14 to 18 mm long. A thin, colorless, adhesive film covering is lost with embryological development. Eggs hatch in approximately 30 days at 30 degrees C. Since the eggs and larvae are retained in the male's mouth until yolk sacs are absorbed, adverse external environmental conditions are supportive actions of the parent. Sea catfish eggs, if left unattended, would be quickly covered by sand and sediment.*79* Yolk-Sac Larvae Sea catfish yolk-sac larvae are normally 29 to 45 mm total length. This stage remains in the male's mouth for 2 to 4 weeks until the yolk-sac is absorbed. The juvenile stages ranged in length from 68 to 88 mm TL for sea catfish. Yolk-sac larvae were collected from adult sea catfish in Life History - 1 (DRAFT) - Life History Species catfish, sea Species Id M010080 Date 27 AUG 96 salinities from 8.33 to 12.78 ppt but not at higher salinities.*79* Larvae A larval stage is considered not to exist since all juvenile morphological features are visible prior to yolk absorption.*79* Juveniles and Adults All adult characteristics are visible at yolk absorption but juveniles remain in or return to their parent's mouths for protection for a short time. Juveniles were found in male mouths in waters of 16.66 to 28.32 ppt. Older juveniles are able to successfully osmoregulate in higher salinities. Juveniles fed heavily on planktonic crustacea either inside or outside parent's mouths. Feeding by males carrying eggs or juveniles has not been documented.*79* Adults Distribution and abundance in gulf coastal and estuarine waters have been related to spawning activities as well as to water temperatures and salinities. Studies indicated that sea catfish were sampled or observed seasonally in greater numbers inshore at higher temperatures (>20 degrees C) and salinities (>20 ppt). Adults avoided lower water temperatures by migrating offshore in winter and returning inshore in the spring. Life History - 2
                           (DRAFT) - Management Practices
                                Species catfish, sea
                                 Species Id M010080
                                   Date 27 AUG 96



MANAGEMENT PRACTICES

COMMENTS ON MANAGEMENT PRACTICES - No management practices were listed for the sea catfish in reference number 79. Management Practices - 1
                                   (DRAFT) - References
                                   Species catfish, sea
                                    Species Id M010080
                                      Date 27 AUG 96



     

References

79* Muncy, R. J., W. M. Wingo. 1983. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of Mexico) -- Sea Catfish and Gafftopsail Catfish. U.S. Fish and Wildlife Service Biol. Rep. 82(11.5) pp 17. References - 1