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

Abstract

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.

Keywords

• Dog snapper
• Mahogany snapper
• Edge-type analysis
• Age-growth