Trichonis rudd (Scardinius acarnanicus)

Economidis, 1991

Order: Cypriniformes
Family: Cyprinidae
Genus: Scardinius

Environment: Freshwater; benthopelagic
Climate: Subtropical; 39°N – 38°N, 21°E – 22°E
Range: 39°N – 38°N, 21°E – 22°E

Description: D III/(7)8, A III/ (8) 9-10, Р I/ (11-13) 14-15 (16)/ I-II (III) or I/ (11-13) 14-15 (16), V II (7) 8, C ( 15 – 16) 17 (18 – 19), L. l. (6) 7(8)/ (40) 41 (42-43) /3 (4), ventral keel scales (6) 7-8 (9), gill rakers 12-17, pharyngeal teeth 3.5 — 5.3, vertebrae (37) 38 (39). Body slender, laterally compressed oval in cross section, whose maximum  height is recorded at the neck region. Distinguished from other species of Scardinius in Balkan Peninsula by: dorsal head profile conspicuously concave, snout pointing upward, tip above level of middle of eye; eye close to or flush with dorsal head profile when viewed laterally; articulation of lower jaw in front of eye margin; and head length 24-30% SL; usually 10½ anal branched  anal rays;  13-16 pectoral rays;  juveniles less than about 70 mm SL with a dark midlateral stripe; 37-42 + 2-3 lateral line scales. Size up to 280 mm SL. The maximum length observed in Lake Lysimachia was 354 mm, corresponding to a 10-years-old female. In Lake Trichonis, the maximum observed observed lenght was 317 mm, corresponding to 8-year-old female.

Distribution: Europe. Endemic to Greece; occurs only in the Acheloos drainage in Etolo-Akanrania and its associated lakes (Trichonis, Lysimachia, Ozeros, and Amvrakia). Recently introduced into Lake Pamvotis, Ioannina.

Biology. Inhabits lakes and large rivers. Spawns for the first time at 140-180 mm at 2-3 years. Fractional spawner. Spawns in March – July. Deposits adhesive eggs on vegetation. Mean egg diameter in Lake Lysimachia was 1.54 ± 0.2 and 1.28 ± 0.16 mm in Lake Thrichonis. Eggs hatch in 5 days. Early larvae and juvenile often form large schools, often mixed with Tropidophoxinellus hellenicus. Phytoplanktophagous when young, whereas as an adult, it becomes macrophytophagous. No difference was observed in the diet of males and females. Maximum reported age: 11 years.


Iliadou, K. and I. Ontrias 1980.  Contribution in the biology of Scardinius erythrophthalmus of the Lakes Lysimachia and Trichonis of the western part of Greece. Biologia Gallo-Hellenica 9(1): 195-205.


 In the present study is given a brief analysis of the of the biology of Scardinius erythrophthalmus of the lakes Lysimachia and Trichonis of the west part of Greece. On the basis of 309 specimens, collected during the years 1977 – 1979, the morphology, the rate of development, the nutricion and the reproduction have been studied, while the following results have been obtained.

1. The examined specimens are distinguished for the great variation of the standard length and the diameter of the eye, while the other morphological characteristics vary less.
2. The morphological characteristics show sexual differences prevailing in the females by 36%.
3. The span life of the specimens of both sexes was found 7 years.
4. The rate of growth is faster during the first years of life and slower in the older years.
5. The average anual growth in length of the females is larger than in males.
6. The average values of the condition factor К is somewhat larger in males than in females. The average value of the condition factor К according to Fulton is is in the males 2.10 while in females 2.08 and according to Klark 1.74 and 1.70 respectively.
7. The adult specimens are feeding on higher plants, while the juvenile individuals on plant plankton.
8. Sexual maturity begins at the age of 2-3 years with body length 14.0 to 18.0 cm and weight 55.0 to 135 gr.
9. The spawning is partial and lasts from March to July. The number of eggs varied from 3.000 to 70.900.