The parasitic coelenterate, Polypodium hydriforme USSOV, from the eggs of the American acipenseriform Polyodon spathula.

Pectoral fin and girdle development in the basal actinopterygians Polyodon spathula and Acipenser transmontanus.

The pectoral fins of Acipenseriformes possess endoskeletons with elements homologous to both the fin radials of teleosts and the limb bones of tetrapods. Here we present a study of pectoral fin development in the North American paddlefish, Polyodon spathula, and the white sturgeon, Acipenser transmontanus, which reveals that aspects of both teleost and tetrapod endoskeletal patterning mechanism...

Unusual intraindividual variation of the nuclear 18S rRNA gene is widespread within the Acipenseridae.

Significant intraindividual variation in the sequence of the 18S rRNA gene is unusual in animal genomes. In a previous study, multiple 18S rRNA gene sequences were observed within individuals of eight species of sturgeon from North America but not in the North American paddlefish, Polyodon spathula, in two species of Polypterus (Polypterus delhezi and Polypterus senegalus), in other primitive f...

Effects of body mass and water temperature on routine metabolism of American paddlefish Polyodon spathula.

This study quantified the effects of temperature and fish mass on routine metabolism of the American paddlefish Polyodon spathula. Thermal sensitivity, as measured by Q(10) value, was low in P. spathula. Mean Q(10) was 1·78 while poikilotherms are generally expected to have Q(10) values in the 2·00-2·50 range. Mass-specific metabolism did not decrease with increased fish size to the extent that...

Evolution of MHC class I genes in two ancient fish, paddlefish (Polyodon spathula) and Chinese sturgeon (Acipenser sinensis).

Here we present the first isolation of major histocompatibility complex (MHC) class I genes from two ancient fish, paddlefish (Polyodon spathula) and Chinese sturgeon (Acipenser sinensis). Seventeen sequences obtained showed high polymorphism and positive natural selection with dN/dS>1. Evolutionary relationships revealed that sequences from paddlefish and Chinese sturgeon distinguished from ot...

Transcriptomic evidence that enigmatic parasites Polypodium hydriforme and Myxozoa are cnidarians