River stingray(Potamotrygonidae)

River stingray(Potamotrygonidae)

River stingrays
Ocellate river stingray, Potamotrygon motoro
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Order:	Myliobatiformes
Family:	Potamotrygonidae Garman, 1877
Genera
Heliotrygon Paratrygon Plesiotrygon Potamotrygon

River stingrays are Neotropical freshwater fishes of the Potamotrygonidae family (order Myliobatiformes).

They are native to northern, central and eastern South America, living in rivers that drain into the Caribbean, and into the Atlantic as far south as the Río de la Plata in Argentina. Generally, each species is native to a single river basin, and the greatest species richness can be found in the Amazon.

River stingrays are almost circular in shape, and range in size from Potamotrygon schuhmacheri, which reaches 25 centimetres (9.8 in) in diameter, to the short-tailed river stingray, P. brachyura, which grows up to 1.5 metres (4.9 ft) in diameter. The upper surface is covered with denticles (sharp tooth-like scales). Most species are brownish or greyish and often have distinctive spotted or mottled patterns, but a few species are largely blackish with contrasting white spots.

They have a venomous caudal sting, and are one of the most feared freshwater fishes in the Neotropical region, sometimes more feared than piranhas and electric eels. However, they are not dangerous unless stepped on or otherwise threatened.

River stingrays are the only family of batoids completely restricted to fresh water habitats; while there are true freshwater species in the family Dasyatidae, for example Himantura chaophraya, the majority of species in this family are saltwater fish.

Species

Potamotrygon leopoldi

The taxonomy of the river stingrays is complex and undescribed species remain.

• Genus Heliotrygon Carvalho & Lovejoy, 2011
  • Heliotrygon gomesi Carvalho & Lovejoy, 2011 (Gomes's round ray)^[1]
  • Heliotrygon rosaiCarvalho & Lovejoy, 2011 (Rosa’s round ray)

Genus ParatrygonA. H. A. Duméril, 1865

• Paratrygon ajereba (Walbaum, 1792) (Discus ray)

Genus Plesiotrygon Rosa, Castello & Thorson, 1987

• Plesiotrygon iwamae Rosa, Castello & Thorson, 1987 (Long-tailed river stingray)

• Plesiotrygon nana Carvalho & Ragno, 2011

• Genus Potamotrygon Garman, 1877
  • Potamotrygon boesemani Rosa, Carvalho & Almeida Wanderley, 2008^[2]
  • Potamotrygon brachyura (Günther, 1880) (Short-tailed river stingray)
  • Potamotrygon constellata (Vaillant, 1880) (Thorny river stingray)
  • Potamotrygon falkneri Castex & Maciel, 1963 (Largespot river stingray)
  • Potamotrygon henlei (Castelnau, 1855) (Bigtooth river stingray)

• Potamotrygon humerosa Garman, 1913
• Potamotrygon hystrix (J. P. Müller & Henle, 1834) (Porcupine river stingray)

• Potamotrygon leopoldi Castex & Castello, 1970 (White-blotched river stingray)

• Potamotrygon magdalenae (A. H. A. Duméril, 1865) (Magdalena river stingray)
• Potamotrygon marinae Deynat, 2006
• Potamotrygon motoro (J. P. Müller & Henle, 1841) (Ocellate river stingray)

• Potamotrygon ocellata (Engelhardt, 1912) (Red-blotched river stingray)
• Potamotrygon orbignyi (Castelnau, 1855) (Smooth back river stingray)
• Potamotrygon schroederi Fernández-Yépez, 1958 (Rosette river stingray)
• Potamotrygon schuhmacheri Castex, 1964
• Potamotrygon scobina Garman, 1913 (Raspy river stingray)
• Potamotrygon signata Garman, 1913 (Parnaiba river stingray)
• Potamotrygon tatianae J. P. C. B. da Silva & Carvalho, 2011
• Potamotrygon tigrina Carvalho, Sabaj Pérez & Lovejoy, 2011
• Potamotrygon yepezi Castex & Castello, 1970 (Maracaibo river stingray)

More Stories:  http://gofishtalk.com/forum/topics/river-stingray-potamotrygonidae

Weather and Tides Forecasts

Weather
The Fishing Website (Fishing.net.nz) has reviewed a number of weather sites and provides the following weather links as some of the better sites we've encountered in our travels on the web. If you have other links you think we should know about and could add to this page please contact us. From time to time links change as sites are updated or improved so if any of these links are longer valid please let us know.

Swell & Wind sites

Check out Swellmap here. Metvue is also a really good weather site - here's the 12 hour NZ rain and wind forcast. Another site worth a look is Marine Weather here.
For an excellent swell forecast for New Zealand go to this page, select Aus/NZ in the mercator slot and you can get theMetService swell forecast up to 180 hrs out. It will also provide an animated forecast if you select that option. Broadband is best for this site.

Forecasts

The metservice provide the current map here. Metservice also provide the same map as a series so you can get an idea of how the next few days will shape up [more]. This link provides options for marine forecasts for your area [more] - use the coastal marine link for a general forecast and the recreational Marine link for more local areas such as the Hauraki Gulf, Wellington, and Christchurch.
The Australian Bureau of Meterology has really good situation and forecast maps. A colour map is here. An animated forecast can be selected for 1 to 7 days from the menu links here.
The best tide site we've come across is here.
TVNZ has an excellent weather summary here. The latest satellite images are updated regularly. The site also has the current analysis, and regional radar images.
Here's a very comprehensive weather site with charts generated by software written and maintained by James McGregor of Victoria University of Wellington.
http://www.windsurf.co.nz/ has live wind strengths and graphs of wind for Auckland, Wellington and Christchurch over the previous few hours. Webcams also on this site so you can check the conditions for some areas before you go.
www.Buoyweather.com is another site that provides a swell forecast - for NZ click here - Now a pay per view site but they do have a free trial option. Swellmap is similar, reliable and free [more].
For live web-cams, check out the NIWA cams here. NIWA provide a network of computer-controlled video cameras that monitor the New Zealand environment for research and resource management - great to give you an idea of what's happening in real-time at a number of locations.
Other good links we've come across:
Cyclone Warnings

South Pacific Swell Forecast

Weather prediction

NIWA weather cam

Sea surface temp charts NIWA - charges apply

Please Note:
Some of these sites recomended contain numerical weather prediction products and may not always reflect official forecasts, especially in the vicinity of weather fronts, tropical cyclones or when significant late-breaking observations have become available to forecasters. These products therefore are intended to be used as guidance only. They have no manual input and are automatically generated from the numerical models. Be safe on the water - if you're unsure about the weather - Don't go!


Source:  http://www.fishing.net.nz/index.cfm/pageid/18/ViewPage/Weather-Tides
More Stories:  http://gofishtalk.com/forum/topics/weather-and-tides-forecasts

Photo

Gamefish weight calculator

To download a printable copy of the full version of these tables click here

These tables are based on the well documented formula that multiplies the length of the fish, multiplied by the square of the widest part of the girth divided by 800 (inches/pounds) This table gives the weights in pounds and kg.
If you have specific comments on these tables please use this thread in our fishing forums - thanks.


Source:  http://www.fishing.net.nz/gamefish-weight-calculator/

Extreme Fishing With Robson Green Season 5 Episode 3