Discover Top Posts Tagged with #aquatic salamanders

Uncharismatic Fact of the Day

Don't ignore the call of the lesser siren! Unlike many salamanders, lesser sirens are vocal, emitting a series of clicks when they approach another member of their species, and may screech or yelp when in distress. The purpose of these sounds is unclear, but they may help lesser sirens navigate their environment or warn others of imminent danger.

(Image: A lesser siren (Siren intermedia) by Kevin Stohlgren)

#lesser siren #Urodela #Sirenidae #sirens #aquatic salamanders #salamanders #amphibians #uncharismatic facts

SNOT OTTER (Cryptobranchus alleganiensis)

Herasimtschuk, D. 2015. “Two male Eastern hellbenders (Cryptobranchus alleganiensis) fight over prime breeding habitat” North Carolina, USA

Better known as the hellbender, the snot otter ain’t no mustelid. Also recognised as the mud dog, lasagna lizard, grampus and several more delightful vernaculars, this sizeable salamander has only its appearance to blame (most notably the thick, slimy folds of skin running down the lateral sides of the animal). I think they’re adorable.

Today I saw some peninsula newts advertised for the aquarium; they are a regional race (named Notophthalmus viridescens piaropicola) of the more widespread red spotted newt, which was formerly more widely availabl to aquarists and exotic pet fanciers. Specifically they are natives of peninsular Florida, and are thus the southernmost populationss amid a wider distribution of N. viridescens as an entire species. Over the wide range of the species, it is noted that the southerly populations have a genetic disposition, to function at higher tempertures than those further north; and it is noted that the southern populations are active and feed all year round, athough with slower digestive passage in cooler temperatures such as 5 to 6 degrees centigrade. It is also worth pointing out that in all populations of N. viridescens, the adult newts are commonest in shallow water, in sunny areas; these newts remain just below the thermocline in the hottest weeks, to evade strong heat. N. viridescens is quite a habitat generalist: they are found in natural ponds and wetlands, and in slow flowing streams, as well as anthropogenic freshwater environments such as canals and ditches. However they are well associated with submerged and emergent macrophytes, and they are averse to fast flowing waters.

Like all other American newts the adults are amphibious and capable of migration between ponds. They will leave ponds to avoid desiccation and heat stress in hot weather, and if living terrestrially their skin cornifies and becomes more glandular, whilst the finnage of the tail decreases. Their behavior when out of the water is to hide amid forest debris and vegetation clumps; they are not in the least fossorial. Of course, the spawning and pre-metamorphic growth of these newts is entirely aquatic, and in ponds which the adults have vacated, the young metaporphose at larger sizes. Upon metamorphosis, N. viridescens famously disperses by an 'eft' (newly metamorphosed juvenile) stage on humid nights; although this is common in some populations and is not seen at all in others. At this time the dispersing efts start to behave as do adults when they are on the land, at which times efts are active above 12 degrees centigrade. (Originally the word 'eft' simply meant a newt in English, though the etymology of this word is actually unknown; the words 'eft' and 'newt' appear to both derive from 'ewte, efete, efeta'. The word 'eft' has since semantically divorced to ro refer to a terrestrial, juvenile life stage that is present in the American newts.)

Peninsula newts are noteworthy for being particularly tied to water, for example in lacking the juvenile eft stage and remaining aquatic; though it is not really remarkable for N. viridiscens living in securely permanent habitats to skip it altogether, because it is merely triggered - like adult dispersals over land - by environmental circumstances forcing unusual habitat use. (Given that adult newts living on land assume eft-like phenotypic traits, and that efts are defined by their metamorphosed status, I personaly consider the concept of an eft as a physically distinct life stage which may be skipped, to be a category error: it is simply that post-metamorphic N. viridescens can cross over land, and adopt appropriate physical traits as they do so.) Adult peninsula newts have been identified on land but this is rare because ot occurs in atypical situations. However they are more commonly found clambering out of the water, upon the floating water hyacinth plants which were was introduced into the range of the peninsula newt during the 1880s. Befitting of an aquatic salamander, sexually mature peninsula newts tend also to possess at a relatively frequent tendency, certain neotenic physical traits, although these tend to be more limited in Notophthalmus than in, for example, the mole salamanders belonging to the genus Ambystoma.

Different N. viridiscens populations may vary as to the environmental conditions, such as pH, that their physiologies are optimised to. However the species as a whole are more likely to remain aquatic in ponds with a more circumneutral pH (above 6) than those with a lower pH of a little above 4. Peninsula newts are sympatric with lesser sirens which prefer a pH between 5 and 6.5, therefore I might suggest peninsula newts to prefer soft and slightly acid parameters. Peninsula newts should do fine in an unheated room temperature tank (that is, 18-22 degrees centigrade), but due to their Floridan origins they are active underwater where tempertures are as high as 26 degrees in the wild. Generally their care and compatibility is as for other newts from ponds and ditches: they are gape limited carnivores that grow 10 to 14 centimeters long, or between about 4 and (rarely) above 6 inches. In my experience, non-breeding adult newts cohabit very well with non-breeding fishes, although some of the latter can nip the gills of neotonic adults, which is not a concern for all peninsula newts. Newts detect foods by chemosensory cues that travel through water easily, so they readily accept defrosted foods and dried preparations, of a suitable nutritional content and size, from the substrate. As many fish are faster swimmers, the newts might not recieve enough foods, if greedy fish take it all first.

#Notophthalmus viridiscens #red spotted newt #peninsula newt #aquatic salamanders #newts #aquatic amphibians