Fishes in MZNA-VERT: freshwater communities in the Larraun river (Spain). PhD project, Javier Oscoz & Master project, A. Cos.

Study Extent

The specimens were captured in eleven sampling points of eight towns (Aitzarreta, Urritza, Iribas, Irurzun, La Ferreria, Latasa, Lecumberri and Muguiro) of the Larraun River in the years 1996, 1997, 1998, 2005 and 2010.

Sampling

The main sampling method was electric fishing. The method used was three-run depletion between two stop-nets. The captured individuals were sedated with 2-phenoxyethanol, identified, counted and measured (total length in mm). Then, fishes were returned to the river. Some specimens were euthanized, studied in the laboratory and deposited on the Museum of Zoology of the University of Navarra (MZNA, Pamplona, Spain). Species identification was performed by J. Oscoz and R. Miranda.

Quality Control

Species identification was performed by R. Miranda and J. Oscoz using suitable literature (Maitland & Linsell 1977) and scientific names were validated using the W. N. Eschmeyer’s Catalog of Fishes (Eschmeyer 2014). Specimens were returned to the river or deposited in the Museum of Zoology of the University of Navarra. Each specimen was labelled with a unique collection number. Darwin test software (v3.3 Ortega-Maqueda and Pando 2008) was used to check out possible mistakes in the coordinates, characters and the format of dates.

Method steps

1. Specimens were sampled following the procedure described in the Sampling description section. The individuales were identified, measured and released in the majority of cases. Some specimens were euthanized and deposited on the Museum of Zoology of the University of Navarra in labelled jars first with formalin and, more recently, with 70% ethyl alcohol. Field data was revised, digitalised and incorporated to the MZNA database (Zootron v4.5, Ariño 1991). The dataset was exported to DarwinCore v1.4 format and revised to correct errors to adequate it to DarwinCore standars. Metadata information was added and the Darwin Core Archive was incorporated to the Spanish GBIF IPT.

In total, 14237 individuals, belonging to eight species, were collected. The most abundant family was Cyprinidae (69%). The other two were Salmonidae (28%) and Nemacheilidae (3.1%). One of the species registered was invasive (Oncorhynchus mykiss) and five were endemic (Barbus haasi, Gobio lozanoi, Luciobarbus graellsii, Parachondrostoma miegii and Barbatula quignardi).

1. Barbus haasi
   common name: Iberian redfin barbel rank: species
2. Gobio lozanoi
   common name: Pyrenean gudgeon rank: species
3. Luciobarbus graellsii
   common name: Ebro barbel rank: species
4. Parachondrostoma miegii
   common name: Ebro nase rank: species
5. Phoxinus bigerri
   common name: Pyrenean minnow rank: species
6. Barbatula quignardi
   common name: Pyrenean stone loach rank: species
7. Oncorhynchus mykiss
   common name: Rainbow trout rank: species
8. Salmo trutta
   common name: Brown trout rank: species

The Larraun river is a 19 km long tributary of the Arakil river (Ebro basin, north of Spain).