ABUNDANCE AND POTENTIAL YIELD OF THE ATLANTIC THREAD 



HERRING, OPISTHONEMA OGLINUM, AND ASPECTS OF 



ITS EARLY LIFE HISTORY IN THE EASTERN GULF OF MEXICO 1 



Edward D. Houde 2 



ABSTRACT 



Eggs and larvae of the Atlantic thread herring, Opisthonema oglinum, were collected in plankton 

 surveys from 1971 to 1974 in the eastern Gulf of Mexico to determine spawning seasons, spawning 

 areas, adult biomass, and potential yield to a fishery. Aspects of the early life history also were studied. 

 Spawning occurred from February to September, but mostly from April through August, when surface 

 temperatures were 22.5° to 30.3°C and surface salinities ranged from 32.4 to 36.8%o. Most spawning 

 took place from the coastline out to the 30-m depth contour, and virtually all spawning occurred where 

 depths were less than 50 m. The area of heaviest spawning was between latitudes 26°00'N and 28°00'N. 

 The most reliable estimates of adult biomass were approximately 110,000 metric tons in 1971 and 

 370,000 metric tons in 1973. The most probable estimates of potential annual yield range from 60,300 

 to 120,600 metric tons. Based on the best larval mortality estimates, more than 99% mortality occurred 

 from time of spawning until 19 days and 15.5 mm standard length in 1973, and approximately 98% 

 mortality occurred for the same period in 1971. 



The Atlantic thread herring, Opisthonema og- 

 linum (Lesueur), is an underexploited clupeid fish 

 that occurs widely in the western Atlantic from 

 southern Brazil to the Gulf of Maine (Berry and 

 Barrett 1963), but is mainly tropical and sub- 

 tropical in its distribution (Hildebrand 1963). It is 

 a coastal species that seldom occurs in depths 

 greater than 90 m and is most abundant in depths 

 less than 35 m (Klima 1971 ). In the Gulf of Mexico 

 it is abundant and its fishery potential has been 

 recognized for many years (Butler 1961; Reintjes 

 and June 1961; Bullis and Carpenter 1968; Fusset 

 al. 1969; Houde 1973a). The total western Atlantic 

 thread herring catch was 12,016 metric tons in 

 1974 (Food and Agriculture Organization 1975), of 

 which 2,434 metric tons were landed by the United 

 States. Some thread herring are landed as inci- 

 dental catches by both Atlantic and Gulf of Mexico 

 menhaden fleets (Klima 1971). Catch statistics 

 are poor for thread herring in the Gulf of Mexico, 

 but only 435 tons were reported in 1973 (Johnson 

 1974). However, 5,000 tons were landed from the 

 eastern Gulf during a 4-mo period in 1967 when a 

 preliminary attempt was made to establish a di- 

 rected fishery. Based on school sightings and catch 



'This is a contribution from the Rosenstiel School of Marine 

 and Atmospheric Science, University of Miami, Miami, Fla. 



2 Division of Biology and Living Resources, Rosenstiel School 

 of Marine and Atmospheric Science, University of Miami, 4600 

 Rickenbacker Causeway, Miami, FL 33149. 



rates by commercial purse seiners, Bullis and 

 Thompson ( 1 967 ) roughly estimated that the total 

 Gulf of Mexico thread herring stock might be 1 x 

 10 6 tons. 



Eggs and larvae of thread herring have been 

 described (Richards et al. 1974) and the species 

 has been successfully reared from egg to juvenile 

 under laboratory conditions (Richards and Palko 

 1969). There was no information on thread her- 

 ring eggs or larvae from the eastern Gulf prior to 

 my research. Kinnear and Fuss (1971) reported 

 seasonal north-south migrations and distribution 

 of thread herring in the eastern Gulf of Mexico, 

 while Fuss et al. (1969) presented data on age, 

 growth, maturity, and food habits of that stock. 

 Fecundity of thread herring in the eastern Gulf 

 was determined by Prest 3 and by Martinez (1972) 

 for fish collected on the Florida Atlantic coast. 



The objective of this research was to obtain a 

 fishery-independent estimate of the abundance 

 and potential yield to fisheries of thread herring in 

 the eastern Gulf of Mexico based on annual sur- 

 veys of eggs and larvae during 1971 to 1974. In 

 addition, information was obtained on spawning 

 seasons and areas, as well as on aspects of their 

 early life history in the eastern Gulf. 



Manuscript accepted November 1976. 

 FISHERY BULLETIN: VOL. 75, NO. 3, 1977. 



3 Prest, K. W., Jr. 1971. Fundamentals of sexual maturation, 

 spawning, and fecundity of thread herring (Opisthonema og- 

 linum) in the eastern Gulf of Mexico. Unpubl. manuscr., Natl. 

 Mar. Fish. Serv., NOAA, St. Petersburg Beach, Fla. 



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