We had some new arrivals at Langford yesterday, when we took delivery of 1100 young rudd, or Scardinus erythrophthalmus, to give them their scientific name. The fish, which were bred and delivered by the Environment Agency have been introduced into Phase 1 and will hopefully grow on to become an important breeding population within our wetland habitat, supplememnting the existing fish populations in the reedbed and they also happen to be one of the favourite food items of bitterns!
They are named after their red or ‘ruddy’ coloured fins and have a blue-green coloured upperside, with silvery undersides – quite an attractive creature! Our fish are currently around 12-15cm in length, but will get as large as 25-30cm and will weigh in the region of 250g at maturity.
The species is native to Eurasia as far as the mid-Asian continent including the Caspian, Aral and Black Seas. It is common and widespread in England and Wales, but not present in Scotland. It prefers sluggish or slow flowing wetland habitats such as lakes, ponds, canals and of course reedbeds, where it lives communally in small groups in shallow water. It is omnivorous and feeds on vegetation and small invertebrates.
The introduced fish should be at breeding age in 2 years time, when they will spawn in May and June each year. The females lay their eggs into water, where they are fertilised externally and then stick to vegetation whilst they develop.
The rudd being transferred into Phase 1 by Langford staff and the Environment Agency.