AGE, GROWTH, AND REPRODUCTION OF 

 THE NORTHERN PUFFER, SPHOEROIDES MACULAV^^^ 



Joanne L. Laroche--' and Jackson Davis^ 



ABSTRACT 



Rings on vertebral centra of the northern puffer, Sphocroides maculaius, were shown to be 

 true year marks. Age groups to V were found in 1,128 specimens collected from Chesa- 

 peake Bay. Females were significantly larger than males at each age. Most growth in length 

 took place during the first growing season from June through October. Sexual maturity was 

 reached at age I. Peak spawning occurred in June and July. 



The northern puffer, Spltoeroides maculatus 

 (Bloch and Schneider), occurs on the Atlantic 

 coast of North America from Newfoundland to 

 Flagler County, Fla. (Shipp and Yerger, 1969). 

 It is the only tetraodontid that is abundant along 

 the middle Atlantic coast and that comprises a 

 large part of the spring and fall commercial 

 catches in Chesapeake Bay. During the period 

 1962 to 1970, total annual landings from Chesa- 

 peake Bay ranged from 1 to 12 million pounds. 

 The steady northward progression of commer- 

 cial landings in the spring from North Carolina 

 to Chesapeake Bay and the southward progres- 

 sion of catches in the fall suggest an annual 

 coastal migration. 



There is little published information on the 

 life history of the northern puffer. Welsh and 

 Breder (1922) reported the food habits, larval 

 development, and weight-length relationships 

 of i)uffers from New Jersey. Shipp and Yerger 

 (1969) reviewed the taxonomy of S. niacidatus. 



This paper describes a technique for determin- 

 ing the age of the northern puffer and reports 



' Contribution No. 525, Virginia Institute of Marine 

 Science, Gloucester Point, VA 23062. 



- This paper is adapted from a thesis submitted in par- 

 tial fulfillment of the degree of Master of Arts, College of 

 William and Mary, Williamsburg, Va. 



^ Virginia Institute of Marine Science, Gloucester Point, 

 VA 23062; present address: Ira C. Darling Center, Univer- 

 sity of Maine, Walpole, ME 04573. 



•* Virginia Institute of Marine Science, Gloucester Point, 

 VA 23062. 



the rate of growth, weight-length relationships, 

 age at sexual maturity, and spawning time. 



This is the first published report of age deter- 

 mination for a tetraodontid. 



MATERIALS AND METHODS 



Age and growth determinations were based 

 on 123 fish captured during November 1969 and 

 1,005 fish collected from April through Novem- 

 ber 1970 from lower Chesapeake Bay, Mobjack 

 Bay, and the mouths of the York and Rappa- 

 hannock rivers, Va. A homogeneous puffer 

 population in the area sampled is assumed. 

 Fish were primarily obtained from commercial 

 pound nets and haul seines but also with a 

 push net, beach seine, and trawl and from com- 

 mercial crab pots. 



Total length was measured from the tip of 

 the snout to the center of the flared caudal fin. 

 Fish with a distended ventral sac were not 

 weighed because water was retained in the sac. 

 Fish were classified as immature, gravid, run- 

 ning ripe, or spent by gross inspection of the 

 gonads. 



In a preliminary study, otoliths, cleithra, 

 opercles, jaw bones, fin rays, and all the verte- 

 brae were removed from a small number of fish. 

 Afterwards only vertebrae No. 2-No. 7 were 

 removed from the fish and were disarticulated 

 and then stained in a solution of 4-8% KOH 

 and Alizarin Red S. The stain reduced glare 

 from the centrum surface and increased contrast 



Manuscript accepted April 1973. 



FISHERY BULLETIN: VOL. 71, NO. 4, 1973. 



955 



