𝔖 Bobbio Scriptorium
✦   LIBER   ✦

The integument of the paddlefish, Polyodon spathula

✍ Scribed by George F. Weisel

Publisher
John Wiley and Sons
Year
1975
Tongue
English
Weight
662 KB
Volume
145
Category
Article
ISSN
0362-2525

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The integument of the paddlefish (Polyodon spathula) is unusual as a relatively small amount of mucus is produced by epithelial cells that are not modified into regular mucous gland cells. A thick compact epidermis and dermis compensate for the slight amount of mucus secreted.

Paddlefish have a variety of scales formed of concentric bony lamellae containing osteocytes. There are five kinds of scales: dorsal and ventral fulcra on the caudal fin, rhomboidal scales on the caudal lobe, horny denticles over the pectoral girdle, calcareous denticles on the trunk, and anchor‐shaped plates on the rostrum. Except for the fulcra, the scales are undoubtedly vestigial.

The numerous surface pits on the rostrum, head, operculum, and throat are epithelial invaginations which are not connected to lateral line canals. No nerves lead to the pits. The spherical to cuboidal and often ciliated cells at the base of the pits are considered to be aplasic cells of unformed neuromasts.

πŸ“œ SIMILAR VOLUMES

Development of the paired fins in the pa
Development of the paired fins in the paddlefish, Polyodon spathula
✍ Paula M. Mabee; Michael Noordsy πŸ“‚ Article πŸ“… 2004 πŸ› John Wiley and Sons 🌐 English βš– 412 KB

## Abstract In __Polyodon spathula__, the pectoral fin radials, with the exception of the metapterygium, are derived from the decomposition of a single continuous cartilage fin plate that is continuous with the scapulocoracoid. This cartilage sheet develops two interior splits to form three precurs

Photoreceptor topography in the duplex r
Photoreceptor topography in the duplex retina of the paddlefish (Polyodon spathula)
✍ Sillman, Arnold J. ;Dahlin, David A. πŸ“‚ Article πŸ“… 2004 πŸ› John Wiley and Sons 🌐 English βš– 415 KB

## Abstract Retinal whole‐mount preparations from the eyes of the North American paddlefish, __Polyodon spathula__, were examined with a combination of bright field and differential interference contrast microscopy. The entire retina was mapped and population counts of rod and cone photoreceptors w

Anatomy and histology of the digestive s
Anatomy and histology of the digestive system of the paddlefish (Polyodon spathula)
✍ George F. Weisel πŸ“‚ Article πŸ“… 1973 πŸ› John Wiley and Sons 🌐 English βš– 1008 KB

## Abstract The paddlefish (__Polyodon spathula__) is one of the most primitive and unique freshwater fishes of North America. It is adapted as a plankton filter‐feeder. The wide mouth and greatly expansible pharyngeal cavity allows it to process a large quantity of water. Numerous setiform gillrak

Rearing Paddlefish Polyodon spathula to
Rearing Paddlefish Polyodon spathula to Maturity in Ponds in the Republic of Moldavia
✍ VitalΓ­ Lobchenko; ArcadΓ­e Vedrasco; Roland Billard πŸ“‚ Article πŸ“… 2002 πŸ› John Wiley and Sons 🌐 English βš– 67 KB

Juvenile paddlefish (Polyodon spathula) hatched in 1988 have been cultivated in ponds up to sexual maturity (age 11+) in Moldavia, located in central European Plain with an altitude ranging from 429.5 m to 147 m. The average annual air temperature is 9.5-10 Β°C and the growing season for pond fish is