Flounder

1. Winter · offshore
   0.25
2. Spring return
   0.55
3. Summer · bays
   0.50
4. Fall · staging
   0.60
5. ● Fall run · C&R only
   0.9058–74°F

1. 1

   small baitfish (mullet, mojarra, anchovies) · baitfish

   primary · finfish

   Diet share

   —

   In season

   Bait equivalents

   cut mullet, finger mullet, mojarra, pinfish

   Season

   Peak May–Oct

   Vulnerable when

   • Moderate on any tide

   Fish lead the adult diet: mullet, menhaden, croaker and killifish. — Overstreet & Heard 1982

2. 2

   shrimp

   secondary · crustacean

   Diet share

   —

   In season

   Bait equivalents

   live shrimp, fresh dead shrimp, shrimp tip, gulp shrimp

   Season

   Peak Apr–Oct

   Vulnerable when

   • High on rising / high slack tide

   Brown and white shrimp are principal items, heavier in smaller flounder. — Overstreet & Heard 1982

3. 3

   bay anchovies (glass minnows) · glass minnows

   tertiary · finfish · Anchoa mitchilli; Anchoa hepsetus

   Diet share

   —

   In season

   Bait equivalents

   small silver spoon, white tied jig, Clark spoon, Gotcha plug

   Season

   Peak Apr–Oct · lull Dec–Feb

   Vulnerable when

   • High on rising / falling tide in calm-to-moderate surf
   • Moderate on high slack / low slack tide

   Bay anchovy is a principal Mississippi Sound prey item. — Overstreet & Heard 1982

Water temp

52–90°F

optimum 70°F

Salinity

0–35 PSU

Feeding

opportunistic

Typical size

14–20"

max 33" total

Lifespan

8 yr

mature at 2 yr

Group feeding

none documented

Cryptic ambusher. Lies buried on mud or sand at drop-offs, dock and jetty bases and pass edges, and strikes passing bait on a moving tide. Eats mostly fish (anchovies, mullet, menhaden) and penaeid shrimp.

Field notes

• Water temperature is the seasonal cue for the fall spawning run, and runs in the northwestern Gulf have shifted later as autumns warm.

  • migration phase: fall run

  — Steffen et al. 2023

• The offshore move peaks mid-October to mid-November, often on cold fronts, and fish funnel through the passes.

  — GCOOS RESTORE species profile; SRAC fact sheet 726

• FWC closes recreational harvest Oct 15–Nov 30 to protect pre-spawning aggregations. The best catching of the year is catch-and-release.

  • month: {"in":[10,11]}

  — FWC flounder regulations; FWC 2022 release

• Gulf flounder (three dark eye-spots in a triangle) share the higher-salinity sand near the passes and count toward the same five-fish bag.

  — FWC flounder regulations (rule covers Gulf, southern, summer and fringed flounder)

• An ambusher on moving tide: a mud minnow or finger mullet dragged slowly along the edge of a dock, jetty base or drop-off is the presentation.

  • tide phase: falling / rising

  — angler heuristic — unverified

Schooling by phase

winter offshore

Adults offshore spawning; few fish inshore

spring return

Fish move back into bays and creek mouths

summer bays

Spread through the bays on mud and sand edges

fall run

Fish concentrate at passes and jetties heading offshore

Citations

1. [1]Steffen et al. 2023 · temperature cue
2. [2]GCOOS RESTORE species profile; SRAC fact sheet 726 · offshore run
3. [3]FWC flounder regulations · fwc closure
4. [4]FishBase SpecCode 981 · max age size 83 cm TL, 9.3 kg, 8 yr; depth 1-43 m; tolerates low salinity; adults mostly over mud
5. [5]Steffen et al. 2023 (Estuarine, Coastal and Shelf Science) · temperature cue temperature is a key seasonal cue; migrations later as autumns warm
6. [6]SRAC fact sheet 726; GCOOS species profile · spawning months Nov-Feb offshore
7. [7]Overstreet & Heard 1982 · diet fishes and penaeid shrimps; Anchoa mitchilli and Penaeus spp. principal
8. [8]FWC flounder regulations; FWC news release 2022 · fwc closure harvest closed Oct 15-Nov 30 to protect pre-spawning aggregations
9. [9]not retrieved · maturity unverified — age 2 is a placeholder