Valencia hispanica (Valenciennes 1846)

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Synonims: Fundulus hispanicus, Hydrargira hispanica (Valenciennes, 1846).

Common and Vernacular names: Samarugo (es), Samaruch (val), Samaruc (lev), Spanish Tooth Carp (eng), Valenciakärpfling (al).

Description: Oblong body, proportionally thin, somewhat depressed in cephalic region and laterally compressed the rest, fins with rounded border, supraterminal mouth with one-apex teeth, irregularly disposed in several rows. Relatively big scales. Brown greenish colour on top becoming lighter towards the lower part of the body. Males have green blue glints, and show a dark spot behind the operculus and some brownish   narrow vertical bars. Odd fins have small yellow-orange colour and have spots on the rays. Females are tender in colour and their dorsal and anal fins are shorter than in males. Longitudinal lie with 28 to 30 scales and transversal line with only 8 or 9.

Meristic formula: D. 10-11; A. 12-14; P. 15; V. 6; C. 18.

Size: They may reach more than eight centimetres, being females usually larger than males of their same age. Usual size in males varies between four and seven cm. 

 
Habitat: Inside their distribution range, they live in slow flowing or stagnant waters, which must be clean, transparent and with abundant aquatic vegetation. Nowadays it is only found in a few springs "ullals" and in the influence zone of these. It used to live in irrigation channels, near the shores of littoral lagoons and even in the middle zone of some Mediterranean rivers (Serpis, Verde, Júcar...). In laboratory conditions it can endure highly saline water (Sanz, 1985) it is rarely found in these conditions in nature, being a characteristic fish of sweet water and not form marshes and brackish waters as the other Iberian cyprinodontids.

 
You can see a  habitat photo selection in our "Imágenes / Images".

 
Geographical distribution: Very restricted in present time. Although there is a very dubious quotation in Colliure (Arnoult, 1957), in historical time it used to live along the Mediterranean coast, form Northern Catalonia, Aiguamolls de l´Empordá (San Miguel, 1979) to the North of Alicante. Nowadays there are only three populations that still survive: Near Peñíscola (Castellón), around the Albufera in Valencia and in Pego-Oliva (Valencia-Alicante). Quotes of samaruc in the Southeast of the Iberian Peninsula and in the Balkans correspond to other species (Fundulus heteroclitus and Valencia letournexi). The origin of some individuals labelled  as coming from Mar Menor (Murcia) is also very dubious, they are kept in the National Museum of Nature Sciences (see Doadrio, I. 1989).

 

Habits and Feeding: Little is known about biological characteristics of this species in the wild, what is known comes from captive research. Adults may swim in small groups, that are not too coherent, males are territorial during the mating season. Young fish live next to the surface, hiding among vegetation. They have a very characteristic way of moving, alternating between quick and short displacements and sudden stops. Their basic diet is composed of small aquatic invertebrates, mainly insects and their larvae, although they also catch terrestrial insects that fall on the water.  

Breeding: It usually happens from April till October. It seems that there are two peaks in their sexual activity, the first of them at the beginning of Spring and the second one at the end of the Summer. As usual, the main factors that trigger reproductive behaviour are temperature (over 17 ºC) and day length (over 11 hours). During this time of the year males show a more colourful pattern, and defend small territories from other rival males. Their ritual fights include a full extension of extension of all fins and a dilation of the branchiostegal membrane. When a mature female is ready and makes contact with one of these territorial males, there is a nuptial dance that consists of semicircular displacements of the male and spasmodic lateral movements of his head. Eggs are laid when both fish approach an adequate substrate such as  feather-like leaves of aquatic plants, filamentous algae, etc. They approach their anus and shivering lay a few relatively big eggs (2-2,5 mm in diameter) that stick to the substrate by way of filaments. From laying till hatching there is little more than one week at normal water temperature this season.
 

Other comments: This species may hybridise with others from the same Genus (Gómez, F. 1995) coming from Albania and occidental Greece, Valencia letournexi, although it seems that the resultant individuals are not fertile. Theoretical calculations indicate that the gap between these two species is around 18 million years (Perdices, A. et al. 1996).

 
Interest: It is a very endangered Iberian endemism, that figures in a list published by the IUCN as one of the 24 most endangered vertebrate species in the World. All the factors that affect this specie's nowadays conservation have a human origin, such as aquatic pollution of different sources (agricultural, urban and industrial), habitat destruction (waterland desiccation, case hardening of irrigation channels and other physical alterations), introduction of exotic species either predators (black bass, Pike-perch, sun fish) or competitors (Gambusia). There is also another  factor, their distribution area is in one of Europe's most populated areas, with big demand on hydric resources during the whole year, which is even bigger during the summer due to the enormous tourists affluence.

 
Protection and present status: Directive 92/43/CE 21st May 1992, about conservation of natural habitats and wild flora and fauna: Annex II (fauna of special interest) and IV (requires strict protection)and "prioritary" in both of them. National Catalogue of Endangered Species (R.D. 439/1990. BOE 5/4/90) "in danger of extinction". D. 21/7/86 of the Valencian Community "protected species". D. 265/1994 which creates and regulates the Valencian Catalogue of fauna endangered species: "endangered of extinction". Protected in Catalonia in the DOGC nº 493 12/12/1984: "protected species".