GENEALOGICAL DECOMPOSITION OF THE EFFECTIVE POPULATION SIZE: A CASE STUDY ON CROATIAN AUTOCHTHONOUS CATTLE BREEDS

Effective population size (Ne) is one of the most important tools used to assess genetic diversity for conservation purposes. Using pedigree data of three Croatian autochthonous cattle breeds (Buša, Istrian and Slavonian Syrmian Podolian) the effective maternal (NeF), paternal (NeM) and combined maternal-paternal (NeFM) population size was estimated. Additionally, we estimated the effective population size based on the census population sex ratio (Nes), the effective population size from the individual increase in inbreeding (NeFi) and the effective population size from individual increase in coancestry (NeCi). We compared these sizes with the values obtained for 20 additional cattle populations, as well as with the newly calculated NeFM. The effective population sizes calculated for three autochthonous breeds were consistently the lowest in amongst all the considered cattle breeds. Utilisation of extremely small numbers of breeding males is the main reason for the observed reduction in the effective population size. The decomposition of effective population size into maternal and paternal components is shown to be an informative parameter in detecting the reduction of the effective population size as a consequence of unequal sex contribution. Still, the impact of the pedigree depth and completeness on the NeF, NeM and NeFM estimation remain to be analysed. A large deviation between Nes and all other methods of Ne estimation was observed and it is our recommendation that breeders and stakeholders should consider using alternative methods of Ne estimation when planning breeding programmes as well as in the determination of the endangered status of animal populations

Ichthyofauna of the lower part of Bliznec stream

Uzorci riba lovljeni su elektroagregatom na donjem toku potoka Blizneca u dva navrata tijekom studenoga 2008. godine. Ukupno je ulovljeno 50 riba. Zabilježene su četiri vrste i to Carassius gibelio, Gobio gobio, Perca fluviatilis i Squalius cephalus, od kojih je S. cephalus najbrojniji. Sve vrste, osim klena imaju negativan alometrijski rast s b vrijednostima nižima od 3. Iako klen ima pozitivnu alometriju, b vrijednost mnogo je niža od hrvatskog prosjeka. I ostale proučavane vrste imaju b vrijednost ispod hrvatskog prosjeka. Faktor kondicije je vrlo nizak i ispod je hrvatskog prosjeka kod klena i grgeča, u prosjeku kod krkuše, a lagano iznad prosjeka kod babuške. Potok Bliznec vrlo je siromašan biotop kako za grgeča tako i ostale proučavane vrste.The fish were sampled in the lower parts of the Bliznec stream using an electroaggregate on two separate occasions in November 2008. A total of 50 fish were sampled. The samples belonged to 4 distinct species: Carassius gibelio, Gobio gobio, Perca fluviatilis and Squalius cephalus. Chub was found to be the most abundant. All species apart from chub were found to exhibit negative allometric growth (b<3), yet all of them exibit a b value lower than the croatian average. CF was found to be very low and below croatian average for chub and perch, average for gudgeon, and slightly above average for prussian carp. The freshwater environment of Bliznec stream was found to be a species poor biotope