Morphometric Changes in Polish Konik Mares After Nearly a Hundred Years of the Breed's Existence.

The study was carried out on 126 mares of the Polish Konik horse breed. Mares were bred under a stable system housing and they came from five leading conservation breeding centres. The mares were divided into three age groups: 3-5 years old, 6-9 years old and over 10 years old. Each animal was characterized using 40 morphometric measurements. Discriminant analysis proved the exterior differences of mares in terms of the analysed metric values. It was concluded that the morphotype of modern Polish Konik mares is statistically significantly influenced by the following traits: neck ventral length, forearm circumference, distance between the vascular notch (incisura vasorum facialium) and the oral angle (angulus oris), distance between the margo coronalis ungulae and the margo solearis ungulae of the thoracic limb, thorax circumference and pelvis width. Conformation traits of the studied Polish Konik mares show multidirectional changes, prevailingly an upward trend in the mean values. However, shoulder height turned out to be definitely the least modified trait. Results obtained in the research presented herein may be a confirmation of progressing exterior transformations, which have been identified in the new generation, namely in the youngest group of mares of this breed.

Comparative anatomy of pectoral girdle and pectoral fin in Russian sturgeon and American paddlefish.

Acipenseriformes occupy an important place in the evolutionary history. Skeleton of their pectoral fins has elements related to teleosts, but also to tetrapods. This article summarises and compares anatomical structure of the pectoral girdle and pectoral fin of Russian sturgeon (Acipenser gueldenstaedtii) and American paddlefish (Polyodon spathula). These species possess pectoral fins with some distinctive features in their structure. The pectoral girdles are composed of both cartilaginous and ossified elements. Unlike sturgeons, American paddlefish does not have an interclavicle and suprascapular cartilage. Moreover, its cleithrum doesn't form medially directed lamina. The quantity of the proximal radials in the investigated fish species are not the same. The dorsal and ventral muscles, which act on the pectoral fin of Russian sturgeon and American paddlefish, are not equally developed. In our opinion, this is caused by the differences in the mode of life, motility of fins, as well as by stabilisation of body during swimming.