FISHERY BULLETIN: VOL 79. NO 4 



CEDAR BAYOU 



Table l. — Description of gonad maturity stages assigned to 

 Cynoscion arenariits. 



Stage and name 



Description 



5 10 15 20 25 



NAUTICAL MILES 



Figure l. — Location of sampling area. Cedar Bayou Pass near 

 Port Aransas is the study location of Simmons and Hoese ( 1959i. 



that 8-12 tows were made at 14-15 m and about 24 

 tows usually were made at 22 m. The 22 m depth 

 primarily was occupied after October 1978. 



Cynoscion spp. were culled from the catch, fixed 

 in 10% Formalin,-* and stored in 70% ethanol be- 

 fore analysis. Cynoscion arenarius was separated 

 from C. nothus primarily by comparing the anal 

 fin base to the eye width following DeVries ( 1979). 

 Total length (TL) was measured on all fish. All 

 specimens captured from October 1977 through 

 December 1978, except as noted, were processed 

 and scales were taken to determine age, standard 

 length (SL), girth (G) at the anterior origin of the 

 dorsal fin, total weight (TW), sex, ovary weight 

 (GW) to the nearest 0.1 g, and gonad maturity 

 stage. In June and early December 1978, 300 

 specimens were randomly selected except that all 

 fish >120 mm TL were processed in June 1978. 

 Scales were taken above the lateral line below the 

 second dorsal fin following procedures for C. re- 

 galis (Perlmutter et al. 1956), and cellulose acetate 

 impressions were examined using a scale projec- 

 tor. Females and immature fish were assigned 

 gonad maturity stages (Table 1) slightly modified 

 from Kesteven's system ( Bagenal and Baum 1971). 



Findings based on collections off Freeport were 

 verified by the following materials. Fish were cap- 

 tured from February through December 1977 and 

 in March, June, and July 1978 off Port Aransas, 

 Tex., aboard the Texas Parks and Wildlife De- 

 partment (TPWD) RV Western Gulf using a 13.7 m 



1 Immature 



2 Maturing virgin 



3 Early developing 



4 Late developing 



5 Gravid 



6 Ripe 



7 Spavi^ning/spent 



8 Resting 



Gonads barely visible or not visible, sexes 



indistinguishable 

 Gonads very small, sexes distinguistied only 



with magnification. 

 Sexes visually distinguished, ovaries occupy 



-: 25% of body cavity individual eggs not 



visible to the naked eye. 

 Ovaries occupy 25-50% of body cavity, eggs 



clearly visible to naked eye. no trans- 

 lucent eggs. 

 Ovaries occupy at least 50% of body cavity, 



up to SO^'o of the eggs translucent. 

 Ovaries occupy at least 50°o of body cavity 



^50% of the eggs translucent. 

 Ovaries flaccid and at least partly empty 



no opaque eggs. 

 Ovaries fit same description as those in 



Stage 3, but fish are large enough and 



were collected at a time when they could 



already have spawned. 



otter trawl with a 5.1 cm stretched mesh cod end. 

 Stations usually were occupied at 11 m at night, at 

 7, 15, and 18-24 m during the day; and also at night 

 at 20-22, 29-31, and 38 m from May through Oc- 

 tober 1977. Additional monthly day collections 

 were made in Galveston Bay, Tex., aboard the 

 TPWD RV Drum II from December 1977 through 

 July 1979 using a 6 m otter trawl with a 3.8 cm 

 stretched mesh cod end or a 3 m otter trawl with a 

 2.5 cm stretched mesh cod end. Finally, collections 

 from July 1978 through July 1979 in Cedar Bayou, 

 Tex., using a 3 m otter trawl with a 2.5 cm 

 stretched mesh cod end were made available by 

 Pridgeon.^ 



Spawned groups and their year class identities 

 were indicated by specifying the season and year 

 when they hatched, e.g., spring 1978. Spawning 

 periodicities and group identities assume that a 

 total length of 30 mm at 1 mo of age for C regalis 

 (Welsh and Breder 1923) applies to C arenarius. 

 Hatching dates of 1 April and 1 September were 

 assigned to spring and late summer spawned 

 groups to estimate growth and ages. 



MATURATION AND 

 SPAWNING PERIODICITY 



Results 



Cynoscion arenarius matures at 140-180 mm TL 

 as they approach age I and spawn. Gonad devel- 



"Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



■■^B. Pridgeon, Graduate Research Assistant, Texas A&M Uni- 

 versity, College Station, TX 77843, pers. commun. December 

 1979. 



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