Sussex Ouse
Flora & Fauna

The tidal Ouse above Hamsey - Picture by Mark Davis SOCS.

The beautiful Sussex Ouse above Hamsey

Flora

Flora is another collective term but this time relating to plant life in a particular area or region.

Plants & Flowers

Trees

Fauna

Like flora, fauna is a collective term for animal life inhabiting a particular area or region.

Birds

Fish

Mammals & Amphibians

Sea Trout (Salmo trutta)

Mature, fresh run Sussex Ouse Sea trout.

Appearance: Just after returning from the sea the fish is very silvery. However, after a few weeks in the river this changes to brownish grey on top, through to silvery yellow on the sides with a mixture of black and some red spots, then white underneath. Average length 15-50cm, 110-120 cycloid scales along the lateral line.
Habitat: Found all over northern Europe . The adult fish need to find suitable gravel stream beds where the female excavates with her tail to form the nest. The male joins her and as the female lays her eggs he fertilises them; about 5,000 are laid. The female then covers them with more gravel to form a raised bed or “redd” which is usually about 50cm across. Eggs hatch after about 2 months and the young fish or “parr” can then spend up to 3 years in fresh water before going to sea. Lives at sea but migrates into the Sussex Ouse to spawn in the tributary streams during the winter. Also migrates into the Uck. Bevern Stream.
Food: Young fish eat most freshwater invertebrates, as adults they will also eat crustaceans and small fish.
Did you know? This is the same species as the Brown Trout, but one that has chosen to migrate and spend part of its life at sea. Important commercially in many areas and widely as a sport fish.

Brown Trout (Salmo trutta)

Small Brown Trout from the Bevern Stream

Appearance: Brownish grey on top changing to silvery yellow on the sides with a mixture of black and some red spots, white underneath. Average length 15-50cm, 110-120 cycloid scales along the lateral line.
Habitat: Found all over northern Europe. The adult fish need to find suitable gravel stream beds where the female excavates with her tail to form the nest. The male joins her and as the female lays her eggs he fertilises them; about 5,000 are laid. The female then covers them with more gravel to form a raised bed or “redd” which is usually about 50cm across. Eggs hatch after about 2 months. Common throughout the middle/upper reaches of the Sussex Ouse and tributaries, pictured here is a small Brown Trout from the Bevern Stream.
Food: Young fish eat most freshwater invertebrates, as adults they will also eat crustaceans and small fish.
Did you know? This trout is the same species as the Sea Trout, but the Brown Trout has chosen to spend all its life in fresh water. Important commercially in many areas and widely as a sport fish.

Common Bullhead – Miller's Thumb (Cottus gobio)

Common Bullhead - Photo by Mark Davis (SOCS)

Appearance: Brownish grey on top, gradually changing to whitish underneath; covered with dark mottling that changes according to background colour. Average length 10-15cm, no scales, but 30-35 pores along the lateral line
Habitat: Found throughout most of Europe , mainly in stony streams. The female lays unusually large, 2.3mm diameter, pale yellow eggs for her size and consequently only about 100 are laid at a time. They are placed in crevices or under stones and guarded by the male. Present throughout the Sussex Ouse catchment and faster flowing tributaries.
Food: Mostly invertebrates, especially insect larvae; also eats fish eggs and small fry.

Did you know? The phrase “Miller's Thumb” is said to date from the time when flour millers gave short weight by tipping the scales with their thumb; presumably the broad somewhat flattened head looks like a thumb. This is “Fish of the Year 2006” in Austria and Germany as it is an indicator of water quality.

Stone Loach (Barbatula barbatula)

Stone Loach - Photo by Mark Davis (SOCS)

Appearance: 6 barbels around the mouth which is on the underside. Dark olive brown mottling on top, gradually changing through yellow grey to a whitish underside. Average length 8-12cm, very small cycloid scales.
Habitat: Found in much of Europe excepting the extreme north and south, in stony streams and rivers. Sensitive to pollution and low oxygen levels. Present throughout the Sussex Ouse catchment and faster flowing tributaries.
Food: invertebrates, especially insect larvae.

Did you know? Each female lays something like 500,000 yellow eggs at a time among the stones and weed of running water. No commercial use, but sometimes used as bait in sport fishing and also as a cold water aquarium fish. In some parts of the USA it is known as the Groundling.

Common Gudgeon (Gobio gobio)

Appearance: 2 barbels at the sides of the mouth. Light olive brown on top with some dark spots; lighter down the sides with a whitish underside. Average length 10-15cm, 40-45 large cycloid scales along the lateral line.
Habitat: Widespread throughout temperate Europe and Asia in rich sandy streams and rivers; also in some lakes and canals. An average of about 2,000 yellow adhesive eggs are laid amongst weed and stones in running water. Common throughout the Sussex Ouse catchment and tributaries.
Food: Mostly eats molluscs, crustaceans and insect larvae; sometimes plants

Did you know? The fish is able to emit squeaking sounds as a means of communication. Sometimes used as bait for sport fishing, but of no commercial importance.

Three-spined Stickleback (Gasterosteus aculeatus)

Three-spinned Stickleback - Photo by Mark Davis (SOCS)

Appearance: 3 strong spines just in front of the dorsal fin. Olive brown back with grey brown mottling on the silvery sides. Average length 4-8cm, no scales.
Habitat: Found in many parts of Europe in areas close to the sea. Will live in a wide variety of waters, even into the sea. The male builds a nest of plant material and then persuades the female to lay her eggs; about 300 yellow eggs are laid and then they are guarded by the male. Found in some of the smaller tributaries of the Sussex Ouse, particularly the Bevern Stream.
Food: Mostly worms, crustaceans and insect larvae; occasionally eats small fish.

Did you know? In the spawning season the male has a bright red belly. This fish is commonly used as a laboratory animal and commercially processed into fish meal and oil in Scandinavia.

Common Minnow (Phoxinus phoxinus)

Common Miinnow - Photo by Mark Davis (SOCS)

Appearance: Brownish green on top with a dark line along the side and whitish grey underneath. Average length 6-10cm, 80-100 small cycloid scales along the lateral line.
Habitat: Found throughout Europe and northern Asia occurring widely in streams, rivers, ponds and lakes. Spawns in shoals over stones and gravel to which the sticky eggs adhere in running water; up to 1,000 eggs are laid. Present throughout the Sussex Ouse catchment and tributaries.
Food: Eats crustaceans and insect larvae and also some plant material.

Did you know? When spawning, between April and June, the male has a bright red belly and white spots on the head. Fished commercially in Russia and used as bait elsewhere; common in aquariums and as a laboratory fish.

Roach (Rutilus rutilus)

Appearance: Greenish brown on top changing to silvery brown on the sides and pale white underneath. Average length 20-35cm, 42-45 large cycloid scales along the lateral line.
Habitat: Over most of northern Europe and Asia including brackish waters of the Baltic, Black and Caspian Seas. Occurs widely in rich ponds, lakes, canals and slow flowing rivers. Roughly 10,000 adhesive yellow eggs are laid amongst weed in shallow water. Both the larvae and adults tend to move around in shoals. Common throughout the Sussex Ouse catchment and tributaries, mostly in the main river, middle and lower reaches.
Food: Will eat both plants and algae, and also many types of invertebrates.

Did you know? In the spawning season the male develops white spots on the head and fins. The fish is caught in nets commercially in parts of eastern Europe, but throughout the UK only of sporting interest. This fish is active and feeds all the year round and so is also a winter and spring opportunity for anglers. Hybridises with the Bream, Bleak and Rudd.

Chub (Leuciscus cephalus)

Appearance: A wide and somewhat flattened head. Dark olive grey on top changing to greenish silver on the sides and yellowish white underneath. Average length 30-50cm, up to 45 large cycloid scales along the lateral line.
Habitat: Throughout central and southern Europe including the brackish water of the Baltic. Found in the middle reaches of rivers and some lakes. About 150,000 adhesive yellow eggs are laid amongst plants and stones in slow flowing water. Common throughout the Sussex Ouse catchment and tributaries.
Food: Mostly invertebrates and plant material when young. The adults eat large invertebrates, fruit and fish.

Did you know? In some parts of Europe it is caught commercially in nets, but in England it is mainly of sporting interest only. The Chub hybridises with the Bleak, a very similar looking fish.

Barbel (Barbus barbus)

Appearance: 4 barbels around the mouth. Brownish green on top changing to golden brown on the sides and creamy white underneath. Average length 25-75cm, 55-65 cycloid scales along the lateral line.
Habitat:

Across middle Europe from England to the Black Sea , mostly in large rivers. Up to 32,000 adhesive yellow eggs are laid amongst stones and gravel in flowing water; the fish usually migrate upstream to spawn. Introduced into the middle reaches of the main Sussex Ouse, found especially in weir pools.

Food: When young will eat worms, molluscs, insect larvae and plant material; adults eat invertebrates and small fish.
Did you know? The Barbel is known by some anglers as the hardest fighting course fish in the river and the eggs are poisonous.

Brook Lamprey (Lampetra planeri)

Brook Lamprey spawning - Photo by Mark Davis (SOCS)

Appearance: The mouth is underneath the head in the form of a sucker and there is a row of 7 gill openings. Grey or golden brown on top with a lighter underside. Average length 10-15cm, no scales. The Lamprey does not have any paired fins and can therefore be easily distinguished from the Eel which has fins just behind the gills.
Habitat: Occurs in much of western Europe in clear streams and rivers with gravel in flowing water; the larvae need sand or silt in which to burrow. The adults make a nest in running water by removing stones with their suckers; about 1,000 clear eggs are laid by each female. Found in the smaller tributaries of the Sussex Ouse, especially in the Uck catchment. This one was photographed spawning in the High Hurstwood Stream.
Food: When in the larval form eats filtered organic material such as algae, but the adults do not feed at all.

Did you know? The larvae live in burrows in the silt for up to 5 years before becoming adults. They then migrate upstream to spawn and die soon afterwards.

Sussex Ouse Flora & Fauna