Wels catfish
📖 Overview
The maximum length of the species has been recorded as 5 m for a long time and the maximum weight as 306 kg . It has been demonstatred that misidentifications and problems of measurment units have led to these numbers. The recorded maxima with evidence are 2.73 m and 130 kg . Inhabits large and medium size lowland rivers, backwaters and well vegetated lakes . Occurs mainly in large lakes and rivers, though occasionally enters brackish water in the Baltic and Black Seas . Found in deep waters of dams constructed on the lower reaches of rivers . A nocturnal predator, foraging near bottom and in water column. Larvae and juveniles are benthic, feeding on a wide variety of invertebrates and fish. Adults prey on fish and other aquatic vertebrates. Attains first sexual maturity at 2-3 years of age . Spawns in the salt water of the Aral Sea (at Kulandy) . Marketed fresh, canned and frozen; can be pan-fried and baked . Locally threatened due to river regulation destroying shallow spawning sites .
🔬 Taxonomy
🐟 Physical Description
Dorsal spines (total): 1; Dorsal soft rays (total): 4 - 5; Anal spines: 1; Anal soft rays: 83 - 95. Distinguished from all other freshwater fishes in Europe by the following unique characters: two pairs of mental barbels; and anal fin with 83-91½ rays. Differs further from the following combination of features: body naked; large, depressed head; dorsal fin with 2-4½ rays; caudal fin rounded or truncate; no adipose fin; and anal rays almost touching caudal . Caudal fin with 17 rays .: elongated.
🌀 Behaviour
Behavioural data for Wels catfish is currently being reviewed.
🦐 Diet
🥚 Reproduction
Males defend small territories in the spawning sites and construct nests made of plant materials. They dig shallow depressions or clean spawning substrate such as willow (Salix) and roots. Males guard the nests until larvae emerge. Spawns in pairs. Eggs hatch in 2-3 days. Larvae live in the nest until yolk sac is absorbed for 2-4 . Eggs are surrounded by a mucous and adherent wrapping. Incubation lasts about 50 hours at 24°C. Egg size 3 mm, larval length at hatching 8.5 mm .
🌍 Habitat & Distribution
Freshwater; brackish; benthopelagic; non-migratory; depth range 0 - 30 m . Temperate; 4°C - 20°C ; 62°N - 36°N, 0°E - 80°E north as southern Sweden and Finland; Aegean Sea basin in Maritza and from Struma to Sperchios drainages; Turkey.
🌿 Ecology
📐 Morphometrics
🌡️ Water Parameters & Tolerance
🛡️ Conservation Assessment
📊 Population Risk & Fisheries
🚨 Invasive Species Impact
- competition with native species
- habitat modification
- management and control costs
- fishery impacts in some areas
Prevention of further spread through import bans, targeted removal in sensitive areas.
Monitoring and containment programs in place.
References: Compiled from IUCN Global Invasive Species Database, USGS Nonindigenous Aquatic Species database, and CABI Invasive Species Compendium.
🎣 Angling Guide
- medium-heavy 7ft spinning rod
- 30-50 lb braid
- fluorocarbon leader
- grass flats
- oyster bars
- marsh drains
- deeper channel edges
Use barbless hooks, minimise air exposure, and revive fish head-first in current before release.
⚠️ Slot limits protect breeding-size fish. Verify daily bag limits.
🍽️ Edibility & Flavour
"Wels catfish is an edible species."
- Clear, bright eyes — cloudy eyes indicate age
- Firm flesh that springs back when pressed
- Fresh ocean smell, never strong or ammonia-like
- Bright red or pink gills, not grey or brown
- Shiny, moist skin with scales tightly attached
- Cloudy or sunken eyes
- Strong fishy or ammonia odour
- Soft, mushy flesh that doesn't spring back
- Discoloured or dry flesh
⚡ Nutrition
Per 100g cooked - Source: USDA FoodData Central
| Nutrient | Amount |
|---|---|
| Protein | 17.1 g |
| Omega-3 (total) | 286 mg |
🔬 Mercury Safety
Mercury data for Wels catfish has not yet been assigned. Please consult FDA/EPA guidance for general seafood safety advice.
🌿 Sustainability
🔬 Full Nutritional Profile
Per 100g - Raw, per 100g - Source: USDA FoodData Central templates (generic fish average)
📊 Population Dynamics
| Year | Region | Index | Notes |
|---|---|---|---|
| - | - | - |
🏆 World Records
| Record Type | Value | Angler | Location | Date | Line Class |
|---|---|---|---|---|---|
| Weight | 144.2 kg | Attila Zsedely | Po Delta, Italy | 19 Mar 2010 | ALL |
Source: IGFA All-Tackle World Records database
🌐 Names & Taxonomy
Scientific Synonyms
| Scientific Name | Author | Year | Status |
|---|---|---|---|
| Siluris glanis | Linnaeus | 1758 | Homotypic |
| Silurus glanis aralensis | Kessler | 1872 | Synonym |
| Silurus silurus | Wulff | 1765 | Synonym |
🔍 Similar Species
🗺️ Global Occurrence Map
Occurrence records from the Global Biodiversity Information Facility (GBIF) - 16 records indexed .
👥 Community & Contribute
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