S'N'A Intermediate Series: Episode 29 - False Water Cobra (Hydrodynastes gigas) - revisited

The False Water Cobra AKA the Brazilian Smooth Snake.
• (Hydrodynastes gigas)
• roughly translated: Hydro (Water) Dynastes (Prince) gigas (Giant) = Giant Water Prince.
• First described by Dumeril, Bibron and Dumeril in 1854 as Xenodon gigas which again roughly translates to Giant (Gigas) Strange Tooth (Xenodon). This is in reference to the paired enlarged grooved teeth to the rear of the upper jaw.
• The genus Hydrodynastes was first used in 1966 by Hoge, the species then bounced between Cyclagras and hydrodynastes (where it has remained since 1999)
• Hydrodynastes belongs to Xenodontidae (Strange Tooths) now synonymous with Disapsidae. Depending on where you read both will be used which is confusing. This makes them cousins of the False or Mock Vipers amongst others such as Xenodon merremi. Which occurs in similar conditions.
• There are 3 recognised species of hydrodynastes:
• Hydrodynastes bicinctus (Hermann’s Water Snake) - Type locality Para, Brazil.
• Hydrodynastes melanogigas (Giant Black False Water Cobra) - Type locality Tocantins, Brazil
• and of course Hydrodynastes Gigas (False Water Cobra) - Type locality Corrientes, Argentina
• This of course charts a huge range North to South. From Belem on the Brazilian North Coast to Corrientes by road it is just short of 4000km.
• Because of this huge changes in the way the climate behaves for these snakes is to be expected.
• Using recorded sightings of the snakes the vast majority of records for H.G occur to the south from Central & Eastern Bolivia, North Eastern Argentina, the majority of Paraguay and a belt across Southern Central Brazil (but not the extreme south of Brazil)
• From this section we have then picked 4 locations to see what happens annually to locale climates in macro view. This of course is not the microclimate but it will help to inform us in some way what the animals face. We will cover this at the end however.
• False water cobras are semi aquatic snakes which specialise in hunting amphibians and Fish but will also accept birds, mammals and other reptiles including snakes. They are adept swimmers and climbers. They also utilize their tail to hunt which is a pretty unique behaviour. Not by luring but by lashing into reeds to spook amphibians out from hiding.
• Facially there are certain features particularly when young that are similar to the more commonplace Thamnophis, Nerodia and Natrix snakes of North America and Europe belonging to Natricinae.
• Similarities end there, the natricine snakes are mildly to heavily keeled snakes with a rough complexion. This snake has glossy smooth scales and feels wonderful to hold.
• This is a large snake, claims have been made of animals approaching 10ft in length. More usually a size of 7-8ft is common place. Because these animals are such great feeders obesity is a real concern. (Give example)
• In captivity this is not a particularly needy snake. It does not like hotter temperatures and would prefer basking opportunities to not exceed 30 Celsius, many keepers have a top end temperature of only 28 Celsius.
• Care must be taken to not make the enclosure too moist, blistering can occur. There is no problem with bathing or even swimming in a paludarium type enclosure as long as the snake can fully dry off after. This is true of most aquatic species kept in captivity. It is down to insufficient air flow in enclosures and bacterial and fungal flourishing.
• Enclosure sizing……
• Substrates, décor, airflow, control.
• Breeding, egg laying (11-14 days pels) incubation (28.5 -70days)
• 9-30 eggs depending upon size of female.
• climate notes.