DAILY TIME OF SPAWNING OF 12 FISHES IN 

 THE PECONIC BAYS, NEW YORK 



Steven P. Ferraro^ 



ABSTRACT 



Diel spawning periodicity occurs throughout the spawning season in 11 of 12 fishes studied in the 

 Peconic Bays, New York. The bay anchovy, An c/ioa mitchilli; Atlantic menhaden, Brevoortia tyrannus; 

 northern and striped seaiohins, Prionotus carolinus andP evolans; hogchoker, Trinectes maculatus; 

 weakfish, Cynoscion regalis; windowpane flounder, Scophthalmus aquosus; and butterfish, Peprilus 

 triacanthus, spawn primarily in the evening or at night. The tautog, Tautoga onitis, and cunner, 

 Tautogolabrus adspersus , begin spawning in the afternoon and spawning continues into the night. 

 Scup, S^enotomus c^T^sops, spawns in the morning, and Atlantic mackerel, Scomfcerscomferus, spawns 

 throughout the day. 



The prevalence of nocturnal spawners in the Peconic Bays is inconsistent with predictions of 

 hypotheses attributing diel spawning periodicity to reproductive isolation and visual constraints. 

 Some possible causes of diel spawning periodicity are reproductive synchronism between the sexes, 

 deleterious effects of sunlight on embryogenesis, and parent or embryo predator avoidance. 



In his review, Woodhead ( 1966) cited several refer- 

 ences indicating that spawning occurs only in the 

 evening or at night in some clupeids, gadids, 

 pleuronectids, exocoetids, and mullets, and only 

 during daylight hours in some gobies, blennies, 

 and pomacentrids. Woodhead concluded: "There is 

 relatively little direct information describing the 

 spawning behaviour of marine fish, but such as is 

 available suggests that spawning is restricted to a 

 particular part of the day." Recent research gener- 

 ally supports that conclusion. 



Simpson (1971) determined the time of day of 

 spawning of four marine fishes from the occur- 

 rence of recently spawned eggs in plankton collec- 

 tions. His results showed spawning occurs in 

 plaice, Pleuronectes platessa, between 1800 and 

 0700 h; sprat, Sprattus sprattus, between 2200 

 and 0600 h; pilchard, Sardina pilchardus , be- 

 tween 2000 and 0200 h; and throughout the day in 

 dab, Limanda limanda, but most intensely be- 

 tween 2400 and 1200 h. Wicklund (1970) observed 

 that natural spawning of small (total length <125 

 mm) cunner, Tautogolabrus adspersus, was re- 

 stricted to between 1200 and 1700 h. A sevenfold 

 difference in numbers offish eggs in night vs. day 

 plankton collections prompted Hobson and Chess 

 ( 1978) to suggest that many reef fishes primarily 

 spawn at night. Ten anchovy species in the Gulf of 



Panama have daily spawning periods lasting 

 about 3 h, and all spawn between about 1700 and 

 0430 h (Simpson 1959). 



Accumulating evidence indicates that diel 

 spawning periodicity is a common phenomenon in 

 marine fishes. In this paper further information is 

 presented on daily spawning times of 12 marine 

 fishes from 10 families. 



METHODS 



From midspring to late fall 1972, 1973, and 1974 

 plankton collections were taken usually at 9-13 

 locations in the Peconic Bay area. Long Island, 

 N.Y. (Figure 1). In 1972 and 1973 samples were 

 taken on two consecutive days at intervals of 5-11 

 days. In 1974 samples were collected at monthly 

 intervals. All collections were made during day- 

 light hours from 0600 to 1735 h e.s.t. At least three 

 vertical plankton-haul samples were taken from 

 the bottom (or to a maximum depth of 12 m) to the 

 surface at each location with a No. 3 (0.333 mm 

 mesh) conical plankton net with a mouth area of 

 0.5 m^. The plankton samples were killed and pre- 

 served in 4% sea water Formalin^ and stored in 1 1 

 glass jars. Surface water temperature and solar 

 time of day (hours since sunrise; time of sunrise 



'Department of Ecology and Evolution, State University of 

 New York at Stony Brook, Stony Brook, NY 11794. 



^Reference to trade names does not imply endorsement by the 

 State University of New York at Stony Brook, Stony Brook, 

 N.Y., or the National Marine Fisheries Service, NOAA. 



Manuscript accepted October 1979. 

 FISHERY BULLETIN: VOL. 78, NO. 2, 1980. 



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