Aquatic Advisory, Greater Kailash, Delhi

15/12/2023

"Bryde's Whale"
-
This was one of the most amazing experiences I've ever had in the water. As with many of my favorite captures, it happened on a day we least expected. Yesterday was a long day, but totally worth the journey for this experience.
-
Special thanks to for once again hosting me on an incredible journey and for letting me use my drone to help find sealife. While I love aerial photography , my true passion is the camera in my hand while I'm in the water. Let me know if you want to join me on a future adventure.

15/12/2023

We came across a striking pair of Swallowtail Headshield Slugs (Chelidonura hirundinina) on our recent trip to Parker Point, Rottnest Island. The name “Swallowtail” derives from a characteristic split in the tail, similar to the tail of its namesake, with the left side always being longer than the right. Headshield slugs have a broad front of the head (resembling a shield, which stops sand from entering the mantle cavity when burrowing). Many marine slugs the Clade Cephalaspidea are voracious carnivores, feeding on nudibranchs, snails, worms, and other slugs 😊

15/12/2023

15/12/2023

15/12/2023

Credit to owner

15/12/2023

16/09/2023

Today, I was asked by an aquarist, why his prize fish, a Moorish idol, Zanckus cornutus, was grazing his Zoanthus polyps. Bedevilled as he was, the answer lies in the biologies of these marine organisms.

A moorish idol will, unfortunately, eat cnidarians that don't sting powerfully, or contain noxious defences. So they will not consume stinging, clown fish hosting anemones or Euphyllia corals, for example. This is the feeding ecology of Zanckus, it is a nibbling grazer of sessile organisms, especially sponges, but also corals. Because such foods are ubiquitous on the reef, these fishes graze constantly, without storing extra for future energy in their body mass.

For this reason, they starve during long haul shipping and acclimatisation, and the stress is the cause of their notorious mortality. When Moorish idols are not subject to such stresses, such as long term captives seeking rehoming, or locally caught fish, they are actually extremely hardly.

In the wild, Zoantbus sp. are pretty much limited to predator free environments, such as rock pools, which is why they are so hardy in aquaria. Their evolutionary history is the story of how they survived by avoiding predators, by colonising difficult habitats. Their retreat to low predation environments, also means these animals have no real defences, against opportunistic grazers from other environments.

Unlikely culprits like Zebrasoma tangs and sargeant majors, will develop a taste in the aquarium, for the unprotected meat of Zoanthus. Whereas the related Palythoa should be safe, for obvious reasons related to their palytoxin, a chemical defence.

Zoanthus are hardy and very suitable for beginners, but very prone to becoming the targets, even of unexpected corallivores. On the other hand, moorish idols are difficult to ship, but they are not inherently hard to keep. If you have one that actually is eating naturally, like a wild fish, it will be tough as boots when it can graze organisms from rocks all day. But one must expect a natural, even if non-obligate corallivore, to consume live corals.

23/05/2023

It is true that decapods obtain shell-building materials from the surrounding water, so in theory, raising the hardness makes sense. But a number of shrimp and crayfish species, in the freshwater tropical aquarium trade, are inhabitants of softer water than people assume out in the wild. They can't need the aquarist to dose very much, unless the water parameters are very off

01/05/2023

Today, I was asked if a plate coral (or fungiid coral, to the zoologist) will kill or consume clownfishes. Fortunately, clownfish species in the wild, have been recognised to faculatively choose plate corals as hosts. Very nice corals and very nice fish, but I found that fungiid tent to start turning black and rotting on the underside. Despite the biotope aquarium, being favorable to their health, in principle. Other than the reputation of Heliofungia as extremely difficult, it isn't clear what causes the tissue dieback. And it seems, for now, either the aquarist has luck with these species, or does not. Other than physically resembling anemones, these stony corals have large mouths, and a macrocarnivorous tendency. Feeding them a swallowable-sized chunk of meaty food, maybe once a week, does them well. Good luck.

18/03/2023

Today, I was asked about the suitability of Canthigaster valentini, and it's congeners, for the reef aquarium. Sadly, despite the repetition of misinformation, this fish is a risk to other motile and sessile reef organisms. Its is considered to be truly omnivorous, consuming a variety of benthic organisms - from filamentous algae, to forams, to poriferans, to polychaetes, to small arthropods. The diet of Canthigaster sp. in the wild, definitely includes coral polyps as well, so these miniature pufferfishes, fall short of reef safe

15/03/2023

Someone is importing Selheim's sole (Brachirus selheimi) into Europe, which is interesting. Because this is a true or pleuronectiform flatfish, indigenous to riverine environments in the tropical North of Australia, and its categorised as a freshwater to estuarine fish. In freshwaters, B. selheimi is reportedly found on shallow, sandy bottoms, and in deeper rock pools.

As a soleid or true sole, B. selheimi is, of course, an ambush predator, consuming small fishes and arthropods. Yet, growing itself to only 25 cms or 6 ins, most intended tankmates should escape predation. Obviously, very small fish or shrimp will not be suitable companions. Not counting predatory habits, pleuronectiforms are passive and peaceful aquarium fishes, so other bottom dwellers in the aquarium, should not be too hectic in their movement.

This species is being traded simply as the 'freshwater sole', which is apt to create confusion, because a number of flatfish species, including mislabelled brackish flatfishes, are sold by this label. The correct common name, is Selheim's sole. Confusingly the species, or a lookalike, is being traded also as the 'Papuan sole'. Given that the tropics of northern Australia and adjacent, southern New Guinea, share many species or species complexes, it would not be surprising if New Guinea exports do represent B. selheimi or extremely similar fish.

Allen et al. (2003) regard Selheim's sole as entirely freshwater, so there's no need to add salt. If one does, it should be at a low salinity, as for guppies rather than for scats and monos. Temperture, pH and hardness values, as for rainbowfishes from the same rivers, should do this species just as fine.

27/02/2023

I have been asked about the ease, or difficulty, of keeping cerianthids - the beautiful tube or fireworks 'anemones' - in the marine aquarium. Fortunately they are easy to care for, although because they are lacking photosynthetic symbionts, they will need feeding with small, meaty pieces, perhaps twice a week.

Cerianthids need only a mild water flow, enough to blow away their wastes. Intense light for them is nsturally unneccessary, because they lack photosynthetic symbionts. However they are best not maintained, under very strong daytime lighting, if you wish to see them extend their crowns out of their tubes. I have maintained them under low and medium light regimens, under which they extended fully by day.

These anthozoans, which are not true sea anemones or actinarians, do need a deep, soft substrate of fine sand or mud, with particles of 4mm or less in diameter, into which they will bury themselves, and withdraw if disturbed. Technically they will be withdrawing into a self-made tube structure. For up to the crown of its tentacles, the cerianthid will secrete a tube of syncretic composition, comprising modified nematocysts, threads of its own musus secretions, and particles of the surrounding substrate.

These anthozoans do have the ability to sting, and the length of their expanded outer or marginal tentacles, means they should be positioned far from sessile animals, such as corals. In the confines of too small an aquarium, they might also sting fish that brush against them, for the venomous tentacles are toxic also to motile animals, such as shrimp and fish - and they will not play host to clownfishes.

Cerianthids use their outer tentacles, to sweep the surrounding substrate for benthic prey, though they do take prey from the water column also. Items thus siezed are transferred from the outer to the inner tentacles, to be passed along further, to the oral cavity for ingestion. The largest prey taken by cerianthids, are probably about 2 centimeters long, and the primary prey of these animals are benthic arthropods, much smaller than that. Some ornamental decapods will thus be in particular danger, from sharing their aquarium, with a cerianthid.

Cerianthids are rarely, if ever, identified to species level in the aquarium trade. More likely they will be vaguely identified, perhaps with a reference to their color as a further specifier, for example, a cerianthid that is a striking purple, will likely be traded as a 'purple fireworks anemone'.

24/02/2023

Today I was, asked about an unusual, bottom dwelling fish traded as a 'lizard blenny'. In fact the fish in question, is known properly as a, sandperch, or Parapercis sp. These, are not a staple import of the marine aquarium trade, so it's unsurprising they are misunderstood to be blennies, and mistraded as such. Another trade name for sandperches, are the sandhopper blennies, though they are emphatically not blennies.

Sandperches are fortunately hardy carnivores, harmless to corals and tridacnid clams, but unfortunately prone to eating their fish and shrimp tankmates. This is in marked contrast to the benthic blennies, that are predominantly algivorous or detrivorous.

Sandperch lack a swim bladder, and as such rest on the substrate. In the wild, they inhabit areas of sand or rubble. This demersal nature is the habit that confuses aquarists, into misidentifying them as blennies. You should consider these ambush predators, more as you would a hawkfish.

The matured size of these fishes unfortunately varies by species, yet the species is unlikely to be identified, at the point of retail. One species I have identified in the trade, P. schauinslandii, the red spotted sandperch, grows to 18 centimeters, or a little beyond 7 inches. However other Parapercis from tropical waters, potentially grow to 'nearly a foot' or short of 30 centimeters. A fish this size may be characterful, but a danger to very small tankmates. They can be fed on defrosted, meaty fare of the sort usually intended, for crustacean- and fish-eating fishes.

I'm actually fond of the sandperch clade, and do not wish to disuade other aquarists from keeping the characterful genus. Other than to caution that they are mis-sold as blennies, even though their dietary habits are dissimilar, and some popular reef tank staples will not be safe when there is a big sandperch lurking around.

15/02/2023

I have been asked about the possibility, of cohabiting a featherfin syno or squeaker catfish, Synodontis eupterus, with discus cichlids, Symphysodon sp. The catfish grows to 30 cms, or 12 ins, so is not suited for too small an aquarium. Many discus owners display their delights, in aquaria that exceed the minimum space requirements for discus. So, it depends.

As water chemistry goes, S. eupterus is from African river basins, where the pH varies from around the value of 7, to approaching that of 9. Fortunately, as a clade, the squeakers are not too fussy, as to water parameters. Given that tank bred and carefully acclimatised discus, are less fastidious than many people assume, there is some 'space' for overlap. Wild S. eupterus inhabit freshwaters with a temperture of about 26 to 31 degrees C, so both fish like higher tempertures than some familiar tropicals.

The difficulty is actually in their activity patterns. Discus are diurnal and sleep on the substrate by night, when the squeakers become most active. Unfortunately, the highly active S. eupterus is too unintentionally disruptive, for the comfort of the placid discus. Cohabiting these cichlids with pimelodids, large loaches, etc, is also problematic

27/01/2023

Today, I was asked about the possibility of cohabiting White's tree frogs, with fishes in a vertical paludarium. Although White's tree frogs aren't aquatic, I'd be wary of them attacking the fish. Instead I'd house smaller tree frogs, or a smaller number of larger, chonkier fish. I've seen White's cohabiting with with flagtail catfish and leopard bushfish, for example. Active fish that size will want a 4 ft long tank, but for sluggish fish that size, it shouldn't really matter

The thing with frogs is, with a few exceptions like Surinam toads and African underwater frogs, their evolutionary history constrained them so that the wider the jaws are, the longer they also are, and basically their prey preference is functionally determined, by the SVL of whatever they can or can't shove inside. As you can see, Whites have proportionally large mouths and also a large body size. They aren't as 'bad' as Budgett's frogs, or North American and African bullfrogs, or Asian horned toads. But they can and do eat intended 'friends' such as geckos. Never underestimate the predatory ability, of any frog with a big face.

https://www.facebook.com/uniladmag/videos/476249274686252/

26/01/2023

Do not overly generalise about soft corals. Alcyoniids, a clade important in the marine aquarium trade, are found on the wave-exposed areas of reef crests on their windward sides, as well as in low flow, sheltered regions in lagoons, and under overhangs were the light intensity is low. In nature octocorals form faunal assemblages, together with scleractinians that had similar requirements to flourish. It is nonsense to speak of soft and hard corals, as having different requirements, as many people do, because they do not understand reef ecology.

Naturally, this diversity results from an extensive degree of niche partitioning among the octocorals, that aquarists often ignore, although It is obviously errant to generalise for all of them. As people do, when wondering why their Fiji leather (probably Sarcophyton elegans) never really flourishes. It's because they assume it can be cared for, as though it were a smoother crowned Sarcophyton species. Whereas the wavy crown off the Fiji yellow, is in fact an adaptation to life in areas of high flow and light, and that the imported coral survives at all in different conditions, is testimony to the hardiness of Sarcophyton sp. in the aquarium

24/01/2023

The gorgonians, a subclade of the octocorals or soft corals, have a reputation as difficult to care for, in the reef aquarium. Such a reputation is partly deserved, since many colonies that are imported, represent species that lack photosynthesizing symbionts. Therefore feeding them sufficiently, dosing an appropriate food, and yet not overburdening the filtration system, together form a challenge. Yet there are also non-photosynthetic alcyonarian colonies, that are notoriously challenging to care for. And this fact has not tainted all of their alcyonarian cousins.

The purple bush gorgonian, as it is traded, is known to marine biologists as Muriceopsis flavida. It is known to divers as the rough sea plume, and Lamarch's Muriceopsis. This species grows in clear, shallow subtital habitats, primarily on patch reefs, primarily in the Caribbean. Records however exist, from as far south as Brazil, so the correct distribution, should be described as tropical Western Atlantic. Wild colonies grow to 75 centimeters or 30 inches tall, and take a bushy, plume-like growth habit. From long main branches, sometimes bearing secondary plumes, M. flavida sprouts stout, stiff pinnules or branchlets, 5 to 8 centimeters long, or from 2 to just exceeding 3 inches. The coloration of a colony may be too pale or dark, to be described as purple, but it is the purple form that is exported for the trade, and aquaculture. Colonies in the wild, are usually no higher than 50 centimeters, or 20 inches.

22/01/2023

The Surinam toad, P**a p**a, is a fascinating, and bizarre looking anuran, from tropical South Anerica. It is related to the African clawed frogs, such as Xenopus and Hymenochirus, and together with them forms the clade Pipidae. Like these Africans, it is an aquatic frog, but there similarities end. Among the anurans, the New World genus P**a, which actually contains a few species, are uniquely specialised suction feeders, that inhale passing prey animals, but cannot maul live victims, or tear into carrion, having lost their ability to bite. To assist their camouflage, P**a sp. are dorsoventrally flattened, and their fingers are transformed into antennae, with star shaped, tactile fingertips.

More alien still to human observers, is P**a's unique method of parental care and birth, called skin brooding. Fertilised spawn are placed into cavities in the skin of the female's back, after which her skin envelops them securely, to prevent their dislodgment. At the point of birth, the offspring P**a burst harmlessly, but grotesquely, out of her dorsal skin. P. p**a births miniature froglets, but congeneric species birth tadpoles that are similar to those of their African cousins, including a carnivorous, filter feeding habit, which is unusual for anuran tadpoles.

Female P. p**a grow to 17 centimeters, or nearly 7 inches, whilst the males are a little shorter, at 15 centimeters, or 6 inches. The diet of this toothless carnivore, is limited to smaller, motile animals, that will fit into the Surinam toad's cavernous mouth. The forelimbs of these frogs, are also employed in prey capture, to form a feeding basket, that attempts to stop prey escaping. Naturally, any prey taken must be small enough for the toad, to ingest in one piece. But the frog will turn on its side, to swallow deep bodied fishes.

08/01/2023

Reed fish (Erpetoichthys calabarica) are cladistians from shaded, vegetated freshwaters in lowland West African rainforest, a biome that grows adjacent to the sea, south of less verdant biomes that are closer to the Sahara. They are sometimes said to be restricted, in the wild, to coastal environments. But this results from an overly narrow reading, of the word 'coastal'.

Zoologically Erpetoichthys is most closely related to the other, true bichirs of the genus Polypterus, which possess pelvic lobe-fins and a fusiform bauplan. Erpetoichthys became more eel-like, and has lost the rear paired appendages. Details of finnage, paired appendages, scalation etc confirm the evolutionary relationship of these unusual genera, which past authorities mistook to be closer to rhipidistians and coelacanth, than is the case. Cladistians possess similar lobe-fins, and true lungs that they use to respire atmospheric air.

In the past this clade includes even giant forms, such as Bawitius from the Cenomanian Kem Kem Formation, a giant that lived among the river dinosaurs Carcharodontosaurus and Spinosaurus, toothy sawskates, mawsoniid river coelacanths, giant lungfishes, and nonmarine leptocleidid plesiosaurs.

They are not at all hard for home aquarists to accommodate in the freshwater aquarium, but they will prey on small fish and shrimps. Larger tetras, cyprinids etc will not be eaten, because their attenuated form, means their gape is small, and most fish tank denizens should be safe.

Based on wild habitats, reedfish ought to be maintained at an ambient temperture of 25 to 30 degrees centigrade, and the pH at 6 to 8. They require dim to diffuse lighting, vegetation and tangles of wood, a soft substrate, and a diet of suitably sized meaty morsels. A further requirement of this species, and other cladistians, is the need to breathe atmospheric air, for it has lungs like those of the tetrapods and dipnoans.

This species is naturally amphibious and is suited to life in a paludarium or aquaterrarium setting, as well as a full aquarium - which will need to have a secured tank lid. Like many eel- or snake-shaped species, they are prone to escaping

02/01/2023

Blue linckia starfish, Linckia laevigata, are one of the ophidasterids that sometimes arrives in the aquarium trade. There are a few species of Linckia sp. and other ophidasterids stars are mistakenly traded under that name. L. laevigata from the Indo-Pacific, however, is traded mostly as a distinctive, bold blue color morph, though the same species is also found in other shades of blue, and in purple and even orange. These echinoderms have a diameter of 30 centimeters or 12 inches across, and their impressive size and bold coloration, had long made them an ubiquitous staple, in marine aquarium retail, before ethical considerations led to a decline in their availability.

L. laevigata always, however, had a poor track record of survival, which was sonetimrs ascribed to an assumed parasitic load, or more often to the unsuitability of captive diets, or the rarity of their obligate diet on 'live rock'. In fact the ophidasterids are grazers of coralline algae and other grazable items, such as encrusting sponges. Not much specific information is available, about the natural diet of L. laevigata itself, but it is very doubtful they might be divergent in this regard, and such foods in fact abound in reef aquaria. In fact, reef tanks tend to have profuse coralline growth, relative to an equivalent area of reef linestone. Yet these beautiful, unfortunate starfish, almost always die, within days of their arrival.

27/12/2022

Today I was asked how to treat an infection of cotton wool 'fungus' (its a saorologeniale) in a freshwater turtle. There are actually two things that can be done.

First is dissolving salt in lukewarm water, to create a medicinal bath. This is because the pathogen is intolerant of high salinities. But the freshwater turtle, though it must be returned to freshwater, can sit in warm salty water for hours.

The second thing is to follow the salt bath, with a beta dine douching. Dissolving beta dine in clean water, at the ratio of 1:10 or so, creates a solution that can gently be dabbed on the affected skin, using cotton wool.

While and after the infection clears up, maintain and improve water quality in the aquarium, to prevent a future infection. But the organisms that are responsible, are far too ubiquitous in freshwater aquaria, to eradicate them from the aquarium microbiome

26/12/2022

The cowries as a whole are a clade of carnivorous grazers, consuming mostly or entirely sponges. However the money cowrie genus (Monetaria sp.) has undergone an interesting dietary shift, into the guild of algivorous snails. They are small for cowries, with the type species, M. moneta, growing to only 3 centimeters long, or a bit over 1 inch, and M. annulus capable of growing to 5 centimeters, or 2 inches.

Both of these species are distributed, from the Indian Ocean coast of Africa, to the Eastern Pacific. In this range the snails are found in shallow marine, and in intertidal habitats, unlike most other animals, exported for the reef aquarium trade. Their importation still occurs, but it is irregular, as they are less useful as algivores, than are the trochoids, such as Turbo, Tectus, Tegula, Stomatella, and Astraea.

Monetaria cowries are so named for the ethnographic significance of their shells, which were formerly used in exchange, by peoples around the Indian and Pacific Oceans. In some parts of that region, this practice actually continues. They are also used in divinatory contexts, making this genus of note to ethnographers and archaeologists. Such importance was historically placed on these shells, that they were transported long distances for the purposes of trade.

Some time ago, these gastropods were faddishly imported as 'reef janitors' for tropical marine aquaria. Although they are indeed algivorous, Monetaria sp. seem to be somewhat fussy in their dietary preferences, selecting only a few species in their natural environments. M. annulus seems to be more of a habitat generalist than is M. moneta, which seems more strictly associated with rocky shorelines.

25/12/2022

Other than the algivororous species such as ceriths and trochoids, probably the most commonly traded gastropods are the nassas, Nassarius sp.,a genus of dog whelks. Especially in the USA, it is the Caribbean Nassarius vibex that is most commonly sold in aquarium stores, though sadly, coldwater species are mistraded either explicitly or implicitly, as N. vibex or as sharing a similar tropical habit. Other species from locations such as Tonga are regularly encountered, though a formal species identification, is rarely if ever attempted. If traded as 'super nassarius' or similar, these nassas can be expected to outsize the diminutive N. vibex, which grows to only 2 centimeters, or 3/4 of an inch, at the most.

Nassas are burrowing snails requiring a fine substrate to dig themselves through. Also as whelks or buccinoids, they have a carnivorous nature, although their appeal to aquarists, is that unlike most whelks, nassa feeding behavior is stimulated by the decomposition of animal tissues. They are thus obligate scavengers, consuming the leftovers of the meaty foods, eaten by most reef fish. Seemingly lacking a raptorial nature, or inclination to rasp sessile animals, nassas are thus regarded as reef safe neogastropods.

25/12/2022

The whelks traded as bumblebee snails, belong to the genus Engina and are rarely traded, with a more precise identification.

Though they are reportedly attracted to crustacean carrion, such as in lobster pots, these snails are considered as specialised predators of encrusting tubeworms. It is said that barnacles, vermerids, and phoronids are ignored by foraging Elgina, which have a specialised method of feeding on the polychaetes, by extending their mouth parts deep down into the tube. In this way, Elgina can handle even large tube worms. However barnacle and decapods fragments, are recovered during the sampling of Engina sp. gut contents.

These pretty whelks may ingest some meaty leftovers, but should not be perceived, relied upon, nor expected to thrive, primarily as 'reef janitors' or 'clean up crew'. However the potential for Engina sp. harming live ornamentals, must be limited at best, given their limited dietary breadth, and small size of perhaps 2 centimeters, or 3/4 of an inch, at the largest

25/12/2022

Episcopal or orange spotted miters, Mitra mitra, are burrowing, predatory gastropods (snails), inhabiting the intertidal and sublittoral zones, and broadly distributed from East Africa to the Red Sea. These snails grow to 14 and sometimes 18 centimeters, up to exceeding 7 inches, though usually under 6. Though the miters are related to such spectacular carnivores, as the ornate mureces and sometimes deadly cones, they are limited to small prey. Though miter diets, are not well researched, a related species of Mitra was discovered to be a specialised predator, of the priapulid worms. Thus the sale of M. mitra as a Nassarius-like scavenger, for inclusion among 'clean up crew', is certainly errant. Survival of M. Mitra in aquaria, is likely determined by the presence of suitable prey in sufficient quantities, among the 'live sand' infauna.

19/12/2022

Blennies are often considered as algivores, and traded as algae grazers, but most blennies are primarily detrivores, and the consumption of algae and/or cyanobacteria, is of secondary importance to them.

Detritus is the most commonly ingested food item among the Blennidae. Though specialised blennies consume other foods, such as worms (Meiacanthus), scleractinian corals (Exallias), or the slime and tissues of other fishes (Aspidontus and Plaguotremus).

The problem is that most blennies that rely heavily upon diets of algae and detritus, are omnivorous enough to consume other foods, and that may create problems in reef tanks. The blennies most specialised to herbivorous or detrivorous diets, tend to be amphibious, shoreline species, unsuitable to a life fully submerged.

More, thin teeth in blennies, simply enable them to scrape non-moving foods, from hard surfaces. Wether it is coral polyps, or algae, or indeed detritus. The algivorous surgeonfishes and corallivorous butterflyfishes, both share this dental morphology.

Cirripectes, Salarias, and Atrosalarias are all coral-safe and serve a utilitarian purpose as detrivores, moreso than algae eaters. Petroscirtes is another coral-safe blenny, an algivore. Blenniella may be similarly reef tank appropriate, based on its stomach contents.

The non-demersal benthic micropredator Meiacanthus, is entirely harmless to corals, as are the few zooplankton-feeding blennies, that are currently included in the genus Escenius, oddly alongside species repeatedly prone to nip ornamental clams, corals, and tube worms. For example E. midas is a coral-safe planktivore. Certain other congeners such as E. lividanalis similarly swim in midwater, and I suspect them also to be zooplaktivores.

13/12/2022

Often mistraded as a "rubber eel", the Rio Cauca caecilian (Typhlonectes natans) is actually an aquatic member, of a primarily fossorial, and non-aquatic clade of vertebrates, the Gymnophiona or caecilians. The confused appellation of "Sicilian worm" is attested, in North American aquarium retail, but these are neither worms nor eels. Rather, they are amphibians, though there is some debate, as to where Gymnophiona fits in the amphibian tree. The bulk of evidence would have Gymnophiona and their fossil relatives, the Albanerpetonidae, as sister to the salamanders, Urodela - forming a descent group, named Procera, that excludes the frogs, Anura.

Ublike their relatives that burrow, the typhlonectids are natural inhabitants of acidic to circum-neutral freshwaters, in the Neotrooical Realm. Ecologically, they are scavengers similar to marine hagfishes, swarming around carrion, and even sharing with them, through convergent evolution, a similar defensive slime coating. Typhlonectes natans also forages prey such as insects, shrimp, frog tadpoles, frogspawn, and small fish. This foraging habit leads to much detritus in their guts, and it is unknown wether Typhlonectes ingest detritus deliberately, or digest decaying plant material for its nutrients. Probably, it is ingested accidentally, in the course of foraging. T. natans grows to around 50 cm (20 in) long.