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Lucy Rees´s Horse
Author: Jorge Lisandro Montiel

 

The action of digging or splanshing the water shown by the horse in the cover of this excellent written book, is a very good example of the genetic memory of horses.

By acomplishing this actions horses try to scare rays off . These kind of river rays inhabit most of South America´s rivers. European horses don´t know these animals. It´s difficult to see a horse not digging the water before getting to plunge itself in the water.



It´s quite easy to see this kind of action in my argentinian pagos, and it´s not really unfrequent to hear that a horse has been beaten o chuciado by a ray. When this happens to them, they start to run desperately, even to the point of death when bumping to a tree or something of the sort. I´ve heard some stories about horses storming through mud houses in their desperate run.

 

  I even had the chance to comment this to the author of this book.

  I´ve compiled some facts about this fish, for you to know it better.

Common name: River ray - POTAMOTRYGONIDAE
There are four known species of this kind: Paratrygon motoro, with tail shorter than its body, brownish colour with black stripes. Paratrygon hystrix, with tail longer than its body and white eyes It´s also commonly named chucho pintado , brave ray o black ray. The other two species are: P. Brachyurus y P. Brumi.

 

These rays defence themselves with a thin and sharp spine located at the back of their tail, so when they feel threatened they curve their tail and body together and sting violently with their stinger. They might also segregate a certain amount of poison or toxic substance, which produces ulcerated wounds that are difficult to heal.


These fishes can be found in the mid Paraná river. The biggest individuals can be observed near the cities of Rosario and Santa Fé, in Argentina.

There is a river in Misiones region (Arg) that Guaraní natives used to call Yaberí, which translated means "the river of the rays" because of the big quantity of this kind of fish that populate its water.

Even if they´re not very frequent, big river rays use to show up every now and then and can complicate the wisest and most cunningly atuned fishermen´s lives.

In general these colossus fish stings when fishing takes place "on the wait" (or a camalote ) and in most cases they cut the nylon nest because the stick to the bottom of the river, making a kind of sucker effect.

EXTERNAL SHAPE Flat head and body, small perpedincular mouth, with teeths placed along 25 (or more) lines.

Dark-brownish colour, sometimes stripped with white marks around its dark edge.

Fins: pectoral fins extended along the two sides of the body, from head to caudal stalk (disc shape). Both right and left pectoral fins are joint from ahead making kind of horn like shape.

 
The caudal peduncle has two stingers by spewing venom secreted by glands in the dermis.

MATING SYSTEM
River rays are ovoviparus fishes, so their reproduction takes place internally. Their eggs develop inside the maternal oviduct, and they . feed from vellum.

The breeding season is around middle autoum. Birth is between november and january, with an estimated quatity of 15 offspring. The female remains close to her offspring all the time.


FEEDING
The most prefered hábitats for rays to feed are river banks and sand beaches in shallow waters, but they also like to gather in non-shallow waters with subaquatic vegetation. Both habitats favour their predating hábits, as they feed from crabs, molluscs, snails and other small fishes.

GENERAL FACTS

River ray´s gills are not covered by operculum, they maintain a ventral position and expel the previosly filtered water through gills in order to absorve the oxygen. The water intake is made through spiracles, or blow holes.

They are cartilagionous fishes: they have a cartilaginous scheleton which is more or less ossified but without getting to obtain a bony structure.

They don´t have a swimming bladder . Gills are covered by an operculum.

 
PRINCIPAL
Aquí su Web
Didácticos
Doma Natural
Escuela Equitación
Hipismo Catalán
Hipismo Español
Hip. Internacional
Jerez 2002
Links
Pony Club
Temas de Cría
Temas Tratados
Venta de Caballos
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