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💧 Freshwater Least Concern 🌡️ Tropical

Drop Knifefish

Gymnorhamphichthys britskii Carvalho, Ramos & Albert, 2011
Max Length
18 cm
Max Weight
-
Lifespan
-
Trophic Level
3.2
Depth
-
Climate
Tropical
Resilience
-
Vulnerability
12.00/100
Typical Length
-
Depth Zone
-

📖 Overview

Drop Knifefish (Gymnorhamphichthys britskii) is a ray-finned fish of the family Rhamphichthyidae. It inhabits freshwater waters. This species can reach a maximum total length of 18 cm. With a trophic level of 3.2, it is a low-level carnivore, feeding on invertebrates and small organisms. It is assessed as Least Concern on the IUCN Red List.

Scientific Name
Gymnorhamphichthys britskii
Authority
Carvalho, Ramos & Albert, 2011
Habitat
Freshwater
Climate
Tropical
IUCN Status
LC
Max Length
18 cm
Trophic Level
3.2
Vulnerability
12.00/100
Salinity
0–0.5 ppt

🐟 Physical Description

This species is distinguished from its congeners except G. hypostomus in having 5-16 (usually 9-13) large dark saddle-shaped pigment bars over the dorsal midline, extending between the nape and a vertical with the end of the anal fin, and sometimes reaching to or slightly below the lateral line; differs from G. hypostomus in having 141-172 (vs. 178-211) anal-fin rays; a shorter snout, preorbital distance 48.1-60.3% of head length (mean 54.6%) (vs. 58.3-68.6%, mean 63.9%); a larger eye, with diameter 5.7-9.0% of head length (mean 7.0%) (vs. 3.3-5.9%, mean 4.3%); a longer distance from tip of snout to posterior nares, 17.1-22.0% of head length (mean19.2%) (vs. 11.2-17.1%, mean 13.8%); 7 (vs. 9-13) displaced hemal spines; and 64-69 (vs. 71-75) vertebrae to end of anal fin .

🌀 Behaviour

Behavioural data for Drop Knifefish is currently being reviewed.

🦐 Diet

aquatic invertebrates
small fish
algae
detritus

🥚 Reproduction

🐣 Oviparous
Spawning Season
spring
Spawn Location
Substrate
Fertilization
External

🌍 Habitat & Distribution

Freshwater; benthopelagic. Tropical South America: Paraguay.

🌿 Ecology

Zone Preferences
💧 Freshwater
Trophic Level
3.2±0.4

📐 Morphometrics

Length–Weight Relationship: W = 0.00269 × L3.07 (TL)
Max TL
18cm

🌡️ Water Parameters & Tolerance

Salinity Range
0–0.5ppt

🛡️ Conservation Assessment

IUCN Category
Least Concern
Assessment Date
2020

📊 Population Risk & Fisheries

Fishing Vulnerability
12.00/100
Low vulnerability
Trophic Level
3.2
Predator
Climate Zone
Tropical
Described By
Carvalho, Ramos & Albert, 2011

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