Spatial and Temporal Distribution of Larval Striped Mullet (Mugil Cephalus) and White Mullet (M. Curema, Family: Mugilidae) in the Northern Gulf of Mexico, with Notes on Mountain Mullet, Agonostomus Monticola

We determined the seasonality, distribution, and abundance of mullet larvae primarily from Southeast Area Monitoring and Assessment Program (SEAMAP) ichthyoplankton surveys of the northern Gulf of Mexico between 1982 and 1986. Although potentially nine species of mullet can occur in the southern portion of the study area, we found only Mugil cephalus, M. curema, and Agonostomus monticola. Mugil cephalus >6 mm SL are separated from M. curema and A. monticola by total number of anal fin elements. Larval A. monticola are separated from M. curema >7 mm SL by having a longer caudal peduncle and pigment on the second dorsal fin at about 13.5 mm SL. Mugil curema and M. cephalus lack pigment on the second dorsal fin until >25 mm SL. Overall, most M. cephalus larvae are collected at stations with surface water temperatures ≤24.7°C (mean: 23.0°C) and salinities ≥34.0‰; most M. curema larvae are collected at stations ≥24.5°C (mean: 26.3°C) and ≥29.9‰. During August 1984, we also found 196 A. monticola (3.6-25.5 mm SL, N = 8 stations) at surface water temperatures of 28.6-29.5°C and salinities of 28.5-35.9‰; we took all larval A. monticola along or west of 93°00′. Adults of all three species of mullet migrate offshore to spawn over or beyond the outer continental shelf. Larval M. cephalus are collected from October to March, but are most abundant during November and December. Mugil curema are collected primarily from April through September but are most abundant during April-May and to a lesser extent August-September; limited spawning occurs during July. Mugil spp. larvae >4.0 mm of both species are collected primarily near the surface, We suggest that based on prevailing current patterns, tag return, and electrophoretic data, M. cephalus spawned in the vicinity of the Mississippi River delta during late fall and early winter help maintain mullet populations in the eastern and western Gulf of Mexico.