Southwestern Arched Mouth Nase

Diagnosis: Lateral line scales (45)47-51(53); above lateral line 10.5-11.5 (12); right pharyngeal teeth (4) 5. In comparison to C. lusitanicum, Chondrostoma almacai has a higher mean number of scales on the lateral line and above the lateral line, a smaller number of right pharyngeal teeth, a smaller head, but a larger snout and eye. There is one allozyme diagnostic locus, PGDH, with the presence of two exclusive and fixed alleles for Chondrostoma almacai (Ref. 55426).

Dorsal spines (total): 3; Dorsal soft rays (total): 7 - 8; Analspines: 3; Analsoft rays: 7 - 8

The new species is a rheophilic fish, inhabiting Mediterranean-type streams that have typical seasonal habitat heterogeneity, and low to medium flowing clear waters. The species has a short life-span living up to four (4) years, and becomes sexually mature early at the age of two years, irrespective of sex. However, 81.5% of males are mature at 70-80 mm total length, whereas only 50% of females are mature at 80-90 mm total length. Magalhães (2002) also noticed high fecundity, apparently strongly correlated with total body length, with estimates of up to 3,999 eggs at 100 mm total length; egg size ranges from 1.12 to 1.43 mm and is independent of total body length. Spawning occurs early in the year, from January to April (Ref. 55426). Breeds in shallow riffle habitats with fast-flowing water. May be confined to very small pools during summer (Ref. 59043).

Iberochondrostoma almacai is a species of cyprinid fish endemic to southern Portugal, where it is only found in the drainages of the Mira, Arade and Bensafrim rivers. It shelters in pools when the rivers shrink in the summer and is threatened by habitat destruction caused by water abstraction and predation and competition from introduced species of fish such as Gambusia, Micropterus and Lepomis.