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Diadromous Least Concern 🎣 Game Fish 🌡️ Tropical 🎣 Game Fish

Purplemouth grunt

Rhonciscus bayanus Jordan & Evermann, 1898
Max Length
51 cm
Max Weight
1.6 kg
Lifespan
-
Trophic Level
4
Depth
-
Climate
Tropical
Resilience
Medium
Vulnerability
42.00/100
Typical Length
33 cm
Depth Zone
-

📖 Overview

Benthic-pelagic species of coastal waters which may enter rivers . Apparently confined to fresh waters, ascending rivers with moderate currents . More abundant near the outlets of rivers and creeks, but not in brackish or marine waters. Reaches at least 640 m elevation and inhabits currents of low to moderate velocity. Feed on crustaceans and fish . Marketed fresh .

Scientific Name
Rhonciscus bayanus
Authority
Jordan & Evermann, 1898
Habitat
Diadromous
Climate
Tropical
Body Shape
Fusiform / normal
IUCN Status
LC
Max Length
51 cm
Max Weight
1.6 kg
Trophic Level
4
Resilience
Medium
Vulnerability
42.00/100
Water Temp
21–30 °C
Salinity
30–40 ppt

🔬 Taxonomy

Genus
Rhonciscus
Rhonciscus
Species
Purplemouth grunt
Rhonciscus bayanus

🐟 Physical Description

Body oblong, somewhat compressed, and not deep (depth contained 3.1 to 3.8 times in standard length); mouth large, terminal, and almost horizontal, its posterior edge located at the same level as the anterior rim of the eye; first gill arch with 7 to 9 gill rakers; dorsal fin notched, with 12 to 13 spines and 12 soft rays (XII-XIII, 12); pectoral fins short, not reaching distal edge of pelvic fins; second anal spine longer and thicker than third; back olive green; belly silvery; entire body iridescent .: fusiform / normal.

🌀 Behaviour

Behavioural data for Purplemouth grunt is currently being reviewed.

🦐 Diet

small fish
crustaceans
cephalopods

🥚 Reproduction

🐣 Oviparous

Oviparous, distinct pairing during breeding .

🌍 Habitat & Distribution

Marine; freshwater; brackish; benthopelagic. Tropical; 21°C - 30°C ; 37°N - Central and South America: Pacific drainages from Baja California, Mexico to Peru.

🌿 Ecology

Zone Preferences
🌊 Marine 💧 Freshwater 🌿 Brackish
Trophic Level
4±0.66
Food Items

crustaceans and fish (Ref

📐 Morphometrics

Length–Weight Relationship: W = 0.00912 × L2.91 (TL)
Max TL
51cm
Max Weight
1,600g

🌡️ Water Parameters & Tolerance

Temperature Range
21–30°C
Salinity Range
30–40ppt

🛡️ Conservation Assessment

IUCN Category
Least Concern
Assessment Date
2020

📊 Population Risk & Fisheries

Population Resilience
Medium
Minimum doubling time
Fishing Vulnerability
42.00/100
Moderate vulnerability
Trophic Level
4
Apex / Top predator
Body Shape
Fusiform / normal
Climate Zone
Tropical
Described By
Jordan & Evermann, 1898

🎣 Angling Guide

Difficulty
Beginner
Fight Rating
strong pulls with head-shakes
Best Seasons
spring,summer,fall
Best Time
incoming tide, dawn and dusk
Line Weight
15-30
Rod Type
medium-heavy spinning
Hook Size
2/0-5/0
Catch & Release
✓ Recommended
Best Months
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Techniques
bottom fishing popping cork soft plastics live bait
Bait & Lures
live shrimp cut mullet soft plastic paddle-tails popping corks
Recommended Tackle
  • medium-heavy 7ft spinning rod
  • 30-50 lb braid
  • fluorocarbon leader
Where to Find Them
  • grass flats
  • oyster bars
  • marsh drains
  • deeper channel edges
Tips & Tricks
Popping cork technique attracts fish from distance. Fish moving tides.
Catch & Release Tips

Use barbless hooks, minimise air exposure, and revive fish head-first in current before release.

Regulations Summary

⚠️ Slot limits protect breeding-size fish. Verify daily bag limits.

📊 Population Dynamics

Year Region Index Notes
- - -

👥 Community & Contribute

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