64 



Fishery Bulletin 100(1) 



al., 1998). Both species are known to begin spawning 

 as early as May and to continue spawning into Octo- 

 ber as determined by maturity indices (e.g. Richards 

 et al., 1979; Wilk et al., 1990). Prionotus spp. eggs and 

 larvae are known to be seasonally abundant above the 

 continental shelf and within some estuaries (e.g. Rich- 

 ards et al., 1979; McBnde and Able, 1994) but eggs 

 and lai-vae are difficult to identify to species on a rou- 

 tine basis. Therefore we took advantage of recently 

 reported morphological information (Able and Fahay, 

 1998) to examine ichthyoplankton collections. 



Our study was designed to examine how spawning 

 patterns varied between two congeners, but intraspe- 

 cific spawning variation also became evident. A sec- 

 ond goal of our study was to examine settlement — to 

 date not reported for either species. Both species un- 

 dergo flexion and complete fin-ray development at 

 about 6-8 mm SL ( Yuschak and Lund, 1984; Yuschak, 

 1985; Able and Fahay, 1998). Separation of prehensile 

 rays on the pectoral fin. a major adaptation for ben- 

 thic feeding (Morrill, 1895; Bardach and Case, 1965; 

 Finger and Kakil, 1985), occurs in fish as small as 12 

 mm SL (Yuschak, 1985). Yet settled juveniles <25 mm 

 SL are rare (Lux and Nichy, 1971; Richards et al., 

 1979; McBride and Able, 1994), which raises the question 

 of whether Prionotus spp. are competent to settle after 

 completing fin-ray development or whether they common- 

 ly delay settlement. Using a novel combination of sam- 

 pling gears, we collected a continuum of late lai-val and 

 early juvenile Prionotus spp. to examine settlement di- 

 rectly. We report for the first time species-specific larval 

 abundances, distributions, ages, sizes, growth rates, and 

 descriptions of early benthic existence. 



Materials and methods 



Collections were made in coastal waters of New Jersey, 

 specifically near Beach Haven Ridge (Fig. 1, Table 1), a 

 prominent sand ridge formation that rises to about 8 m 

 depth and is surrounded by depths of 14-16 m (Stahl et 

 al., 1974). Sampling frequency at two stations, one land- 

 ward and the other seaward of the ridge, was every two to 

 six weeks from July 1991 to November 1992. Two tows of a 

 Tucker trawl ( 1 m-i were made at each station in a double, 

 stepped-oblique fashion. One tow was made from the sur- 

 face to the bottom (three minutes duration) and the other 

 tow was fished from the bottom back to the surface (six 

 minutes). Newly settled juveniles and older fishes were 

 sampled with a 2-m beam trawl in Great Bay estuary, near 

 Beach Haven Ridge, as well as in other habitats (Fig. 1). 

 The data from these stations were arranged in the follow- 

 ing gi'oups: 1) the two principal ridge stations (described 

 above); 2) miscellaneous stations scattered on top of and 

 around the ridge; 3) stations along a transect leading 

 directly offshore from the ridge; and 4) a cluster of stations 

 within nearby Great Bay. Generally, three tows were com- 

 pleted at stations immediately landward and seaward of 

 the ridge, but only two tows were completed at other sta- 

 tions. Beam trawl tows offshore of Little Egg Inlet took 



Figure 1 



Map of sampling station locations in southern New Jersey, including 

 the main stations at Beach Haven Ridge (landward and seaward: filled 

 circles), other ridge stations (open circles), continental shelf transect 

 stations (filled triangles), and estuarine stations (open triangles). The 

 state of New Jersey, and the study location, are shown in the inset. 



one minute to complete, but estuarine tows were reduced 

 to 20 or 30 seconds to avoid collecting large volumes of 

 macroalgae, detritus, shell, etc. Sampling occurred during 

 daylight unless otherwise stated. Details of sampling pro- 

 cedures are provided by Hales et al.' Volume or area 

 sampled was calculated by using a flow-meter for ichthy- 

 oplankton collections or a meter wheel for beam trawl 

 collections. Larval density is presented as the geometric 

 mean number of fislVm' for Tucker trawl collections. Juve- 

 nile density is presented as the geometric mean number 

 of fislVm- of sea bottom. Calculations of geometric means 

 follow Sokal and Rohlf ( 1981). 



The standard length (SL) of all, or at least 20 fish per 

 tow, was measured after the fish were presei-ved in 95'^?- 

 ETOH. The term "lai'va" was used in reference to individu- 

 als collected in Tucker trawl tows. Preflexion larvae were 

 distinguished from flexion lai-vae by the absence or pres- 

 ence, respectively, of cartilaginous urals on the ventral 

 edge of the notochord tip; the development of these urals 

 accompanied flexion of the notochord tip (Kendall et al., 

 1984 ). Larvae were characterized as postflexion stage once 

 the notochord tip moved anterior to the posterior edge of 

 the hypurals. 



Daily age was estimated from counts of sagittal otolith 

 mici'oincrements, which were validated as daily by Mc- 

 Bride.- Otoliths with a maximum length less than about 



Hales. L. S., Jr., R. S. McBride, E. A. Bender, R. L. Hoden, 

 and K.W.Abie. 1995. Characterization of non-target inverte- 

 brates and substrates from trawl collections during 1991-1992 

 at Beach Haven Ridge (LEO-1.5) and adjacent sites in Great 

 Bay and on the inner continental shelf ofT New Jersey. Techni- 

 cal report (contribution 95-09). 34 p. Institute of Marine and 

 Coastal Sciences, Rutgers, The State University of New Jersey, 

 New Brunswick, NJ. 

 ' McBride, R. S. In review. Spawning, growth, and ovei-wintering 

 size of searobins (Triglidae: Prionotus carolinuK and P. evolans). 



