Age, growth, mortality and reproductive seasonality of jolthead porgy, Calamus bajonado, from Florida waters.

Ages of jolthead porgy (Calamus bajonado Schneider 1801) (n = 635) from Florida commercial and recreational fisheries from 2008-2016 were determined using sectioned sagittal otoliths. We determined, using edge-type analysis, that opaque zones were annular, forming March-June (peaking in April). Jolthead porgy ranged from 1-13 years, and the largest fish measured 680 mm TL (total length, mm). Body size relationships for jolthead porgy were TL = 1.09FL + 20.44 (n = 622, r2 = 0.99), FL = 0.90 TL -14.26 (n = 622, r2 = 0.99), and W = 1.1 × 10-5 TL3.06 (n = 577), where W is total weight (grams, g) and FL is fork length (mm). The von Bertalanffy growth equation for jolthead porgy was Lt  = 737(1 - e-0.14(t+2.02)) (n = 635). Point estimate of natural mortality was M = 0.32, while age-specific estimates of M ranged from 0.58-0.17 y-1 for ages 1-13. Catch curve analysis estimated the instantaneous rate of total mortality Z = 0.70, while instantaneous rate of fishing mortality F was 0.38. Macroscopic staging of female gonads indicated the presence of hydrated oocytes from December-March, and GSI data indicates that peak spawning in females occurs during March. This study presents the first published findings of life history parameters for jolthead porgy from the Atlantic waters off the southeastern United States.

Preliminary observations on the age and growth of dog snapper (Lutjanus jocu) and mahogany snapper (Lutjanus mahogoni) from the Southeastern U.S.

Dog snapper (Lutjanus jocu Bloch and Schneider 1801) and mahogany snapper (Lutjanus mahogoni Cuvier 1828) are infrequently caught snappers in the southeastern U.S. primarily occurring off of southern Florida. The species were opportunistically sampled from commercial and recreational fisheries in the southeastern U.S. from 1979 to 2015. Fish were aged (56 dog snapper and 54 mahogany snapper) by counting opaque zones on sectioned sagittal otoliths. Otoliths of both species were easily interpretable and agreement between readers was acceptable. Analysis of otolith edge-type revealed that annuli formed between May and July on both species. Dog snapper ranged from 200-837 mm total length (TL) and ages 2-33, while mahogany snapper ranged from 270-416 mm TL and ages 2-18. The Von Bertalanffy growth equations were Lt  = 746(1-e(-0.20(t-0.32))) and Lt  = 334(1-e(0.31(t+1.19))) for dog snapper and mahogany snapper, respectively. The weight-length relations were W = 1.31 × 10-5L3.03(n = 78, r2 = 0.99) and W = 5.40 × 10-6L3.15(n = 79, r2 = 0.79) for dog snapper and mahogany snapper, respectively, where W = whole weight in grams.

Age, growth, and natural mortality of schoolmaster (Lutjanus apodus) from the southeastern United States.

Ages of schoolmaster (n = 136) from the southeastern Florida coast from 1981-2015 were determined using sectioned sagittal otoliths. Opaque zones were annular, forming March-July (peaking in May-June). Schoolmaster ranged in age from 1-42 years; the largest fish measured 505 mm total length (TL) and was 19 years old. The oldest fish measured 440 mm TL. Estimated body size relationships for schoolmaster were: W = 9.26 × 10-6TL3.11 (n = 256, r2 = 0.95); W = 2.13 × 10-5FL2.99 (n = 161, r2 = 0.95); TL = 1.03 FL + 10.36 (n = 143, r2 = 0.99); and FL = 0.96 TL - 8.41 (n = 143, r2 = 0.99), where W = whole weight in g, FL = fork length in mm, and TL in mm. The fitted von Bertalanffy growth equation was: Lt = 482 (1 - e-0.12(t+2.79)) (n = 136). Based on published life history relationships, a point estimate of natural mortality for schoolmaster was M = 0.10, while age-specific estimates of M ranged from 1.57-0.18 for ages 1-42.

Age, growth, and natural mortality of yellowfin grouper (Mycteroperca venenosa) from the southeastern United States.

Ages of yellowfin grouper (n = 306) from the southeastern United States coast from 1979-2014 were determined using sectioned sagittal otoliths. Opaque zones were annular, forming January-June (peaking in February-March). Yellowfin grouper ranged in age from 3 to 31 years; the largest fish measured 1,000 mm fork length (FL). Body size relationships for yellowfin grouper were: W = 1.22 × 10(-5) FL(3.03) (n = 229, r (2) = 0.92); TL = 1.06 FL - 14.53 (n = 60, r (2) = 0.99); and FL = 0.93 TL + 18.63 (n = 60, r (2) = 0.99), where W = whole weight in grams, FL in mm, and TL = total length in mm. The von Bertalanffy growth equation was: Lt = 958 (1 - e(-0.11(t+2.94))) (n = 306). The point estimate of natural mortality for yellowfin grouper was M = 0.14, while age-specific estimates of M ranged from 1.59 to 0.17 for ages 1-31.

Age, growth and natural mortality of coney (Cephalopholis fulva) from the southeastern United States.

Coney (Cephalopholis fulva) sampled from recreational and commercial vessels along the southeastern coast of the United States in 1998-2013 (n = 353) were aged by counting opaque bands on sectioned sagittal otoliths. Analysis of otolith edge type (opaque or translucent) revealed that annuli formed in January-June with a peak in April. Coney were aged up to 19 years, and the largest fish measured 430 mm in total length (TL). The weight-length relationship was ln(W) = 3.03 × ln(TL) - 18.05 (n = 487; coefficient of determination [r (2)] = 0.91), where W = whole weight in kilograms and and TL = total length in millimeters. Mean observed sizes at ages 1, 3, 5, 10, and 19 years were 225, 273, 307, 338, and 400 mm TL, respectively. The von Bertalanffy growth equation for coney was Lt = 377 (1 - e ((-0.20(t+3.53)))). Natural mortality (M) estimated by Hewitt and Hoenig's longevity-based method which integrates all ages was 0.22. Age-specific M values, estimated with the method of Charnov and others, were 0.40, 0.30, 0.26, 0.22, and 0.20 for ages 1, 3, 5, 10, and 19, respectively.