OLLA and SAMET: COURTSHIP AND SPAWNING BEHAVIOR OF TAUTOG 



that the dominant male was dying (unknown 

 causes). This latter animal was obviously in a 

 weakened condition and did not participate or in- 

 terfere with the reproductive activities during his 

 last day of survival. In Study 2, as described above, 

 the subordinate male initiated courtship and 

 spawning with the female at the onset of the re- 

 productive season and continued until the aggres- 

 sion by the dominant literally suppressed all of his 

 normal behavior. 



The behavior exhibited by each subordinate 

 male immediately prior to and during spawning 

 was essentially comparable to that of the domi- 

 nant, except that it was less stereotyped. Some- 

 times during a run the subordinate male weaved 

 from one side of the female to the other; and in 

 other cases he actually swam ahead of her on the 

 first and second runs. Gradually as the male came 

 to align himself more with her position, the male 

 initiated flank contact, and positioned his body 

 slightly above hers. 



In both studies, once this continuous contact by 

 the subordinate male was maintained, the runs, as 

 discrete behavioral patterns, were no longer dis- 

 cernible. Generally the pair swam in a meander- 

 ing, zig-zag pattern in midwater, and eventually 

 circled approximately 0.5 to 1.0 m below the sur- 

 face. During this behavior, it always appeared 

 that the male was herding the female. Generally, 

 because the pair was now so close to the surface, 

 the final movement upwards covered only a short 

 distance. 



The subordinate male of Study 1 was last ob- 

 served to spawn with the female on 25 July 1975, 

 comprising an estimated total of 57 spawning days 

 for this pair. Conversely, the subordinate male of 

 Study 2 completed only 4 days of exclusive paired 

 spawning with the female before the dominant 

 male took an active role in the reproductive 

 activities. 



DISCUSSION 



It is well known that light and temperature play 

 a role via the neuroendocrine system in both ini- 

 tiating and synchronizing reproduction in fish (see 

 review and discussion by de Vlaming 1974). How- 

 ever, spawning occurred in the laboratory even 

 though the fish previously had been exposed to an 

 unnatural photoperiod and temperature. Temper- 

 atures were, in fact, at high, stressful levels. It is 

 possible that the endocrinological events as- 



sociated with gonadal recrudescence may have 

 been initiated 8 to 10 mo or more before the fish 

 were captured. The photoperiod in the laboratory 

 was eventually lengthened and regulated to keep 

 apace of the natural changes beginning 16 days 

 (Study 2) to 56 days (Study 1) before the first 

 spawning. Temperatures of 18° to 20°C, well 

 within levels at which eggs have been found in 

 nature (Perlmutter 1939; Williams 1967), were 

 maintained 93 days (Study 2 ) to 126 days ( Study 1 ) 

 prior to the onset of spawning. 



Previously published field observations indicate 

 that tautog spawn sometime between May and 

 June in the waters of New York (Olla et al. 1974; 

 Briggs in press) and Rhode Island (Chenoweth 

 1963; Cooper 1966), with June being the principal 

 spawning month in Massachusetts waters (Kuntz 

 and Radcliffe 1917; Bigelow and Schroeder 1953). 

 These spawning dates are supported by data based 

 on collections of eggs and larvae from Sandy Hook 

 Bay estuary (Croker 1965) and are further ex- 

 tended through mid-August based on similar col- 

 lections from Long Island Sound (Wheatland 

 1956; Richards 1959). 



That the fish spawned earlier in the laboratory 

 than they would have in nature supports the sup- 

 position that the final synchrony may depend on 

 proximal environmental cues. While the gonadal 

 recrudescence may have been initiated by events 

 occurring in nature prior to capture, final syn- 

 chronization may have been caused by the 

 changes in temperature and the advancing photo- 

 period. Because the study was not designed to 

 examine such questions, assignable causes of the 

 spawning occurrence must be conjectural. 

 Nevertheless, whatever the causative environ- 

 mental events, the animals did achieve reproduc- 

 tive synchrony. 



To date there are no specific descriptions of 

 spawning behavior in the tautog. In a laboratory 

 study on tautog in June 1967, Bridges and Fahay 

 (1968) reported that during a 10-day period, a ripe 

 female and male both underwent a shading 

 change between 1500 and 1630 and exhibited be- 

 havior which the authors described as possible 

 courtship. Our observations concur with these au- 

 thors with respect to the daily afternoon shading 

 alteration of the female. However, their descrip- 

 tions of the behavior suggested aggressive in- 

 teractions between the two animals and thus the 

 male's shading more likely reflected an animal 

 involved in aggression rather than courtship. The 

 female and male's behavior further suggest that 



595 



