Topmouth Gudgeon Care Guide
Pseudorasbora parva is a hardy East Asian cyprinid, listed as an invasive alien species of concern in the EU.
Overview
Pseudorasbora parva, the topmouth gudgeon or stone moroko, is a small cyprinid native to East Asia. According to FishBase and Wikipedia it is a hardy species with a superior (upturned) mouth that has become widely invasive outside its native range. It is rarely kept in the ornamental trade because of its invasive potential.
Taxonomy
- Family: Gobionidae (formerly placed in Cyprinidae)
- Genus: Pseudorasbora
- Scientific name: Pseudorasbora parva (Temminck & Schlegel, 1846)
- Common name: Stone moroko (FishBase)
Habitat
FishBase records the native range from the Amur to the Zhujiang (Pearl River) drainages across Siberia, Korea and China. Wikipedia adds Far East Russia and Taiwan. It is a freshwater, benthopelagic fish of temperate waters that has been introduced and become invasive across Europe and parts of Asia.
Tank requirements
- Minimum tank volume: 100 L (about 26 gal)
- Temperature: 4-24 °C (39-75 °F)
- pH: 6.5-8.0
- GH: 8-20 °dGH
- School size: at least 6 individuals
- Maximum length: about 12.5 cm TL (FishBase)
- Lifespan: 4-6 years
Diet
The species is an omnivore (FishBase trophic level 3.1). FishBase reports it feeds on small insects, fish and fish eggs as well as plant material. Predation on the eggs of native fishes is one reason it is regarded as an ecological pest.
Compatibility
The topmouth gudgeon is peaceful and shoaling, occupying the middle water column, and is plant-safe. It is cold-tolerant and suits unheated tanks with species such as White Cloud Mountain minnows; it should not be mixed with strictly tropical fish or kept with delicate small fish whose eggs it may eat.
Breeding
FishBase reports it breeds in still or slow-flowing water, with females spawning three to four times in a season and males guarding the eggs until they hatch. Its high reproductive rate contributes to its invasiveness.
Conservation status
IUCN Red List: Least Concern (assessed 2020). Wikipedia notes that since 2016 it appears on the European Union list of Invasive Alien Species of Union concern, which prohibits its import, breeding, transport, sale and release within the EU.