Congo Caecilian

## About

A Congo caecilian in leaflitter.

The Congo caecilian ***(Herpele squalostoma)*** is a species of serpentine, legless amphibian belonging to the order gymnophiona. Similarly to other caecilian species, the Congo caecilian possesses very apparent segments, also called annuli. It has <135 of these primary annuli that wrap fully around the cylindrical body in segments and an additional 12-45 secondary annuli, which do not form segments. Comparatively to other caecilian species, the Congo caecilian possesses a prominent snout and a rather disproportionately small head. The Congo caecilian is blind, actually having no visible eyes, as they are covered by bone, rendering them invisible externally. They are the only African caecilian to exhibit this attribute. Individuals likely differ in appearance, as some sources describe a greyish-olive appearance, including faint yellow patterning, whilst much of the photographs of the species depict a more pink and purple animal. The Congo caecilian's holotype remains one of the only references to the species' appearance and measures to 41cm (16in) in length. This size may differ between individuals.

## Conservation Status

There is currently an undetermined number of Congo caecilians circulating in the pet trade. Due to the enigmatic nature of the species' status in the pet trade, it is unclear how much of a threat it posses to the Congo caecilian. Other threats exist also in the form of habitat degradation, particularly in Gabon, where the species is endangered by oil drilling and deforestation practices. Another population in Cameroon is threatened by the influx of Batrachochytrium dendrobatidis (Bd) which some individuals have tested positive for. This is significant, as it implies the possibility that Congo caecilians may be susceptible to chytridiomycosis, a disease which irritates the skin of its amphibian host to a lethal degree. Chytridiomycosis is also found in similar species, further implying its presence in the Congo caecilian population. Despite these threats, the Congo caecilian remains a least concern species, according to the IUCN.

## Range and Population

Unlike the majority of caecilians, the Congo caecilian is not an exclusively aquatic, or even semi-aquatic species, as it is actually more commonly found in terrestrial environments, in fact, it is a fossorial species, typically living underground. As its name suggests, the Congo caecilian is known to inhabit the Congo jungle, it is found in the countries of the Republic of the Congo and the Democratic Republic of the Congo (D.R.C.) however, it also occurs in Gabon, Cameroon, Angola, Nigeria, the Central African Republic (C.A.R.) and Equatorial Guinea. Interestingly, the species is not native to the mainland and can also be found inhabiting the island of Bioko, Equatorial Guinea. The species inhabits the same environments no matter its range, being abundant in lowland forests, rainforests and inland wetlands and it is known to occur at elevations of 0-800m (0-2,624.67ft) in Cameroon particularly. The Congo caecilian's population is unclear but thought to be large however, ongoing threats have caused their population to be in decline.

## Behaviour

Congo caecilians are likely similar to other caecilians in that they are oviparous, although this has not been proven. Their young are hatched completely formed, skipping the larval stage. Evidence such as the lack of fetuses or embryos and the lack of larval features in juveniles support these hypotheses. The Congo caecilian exhibits maternal dermatophagy, where the mother will grow a fatty layer of protective skin for the purpose of letting their young feed off it. This possible behaviour is not only supported by the fact that other caecilian species are known to do this, but also that stratum corneum, the outer most layer of skin, has been recorded in the stomachs of juvenile Congo caecilians. This strategy has proven to be effective, as juvenile caecilians have been observed gaining weight and growing from this interaction, even without the introduction of other foods. Juveniles are born with deciduous, multi-cusped and polystichous teeth as well as proportionately large jaw muscles. This anatomy and dentition is common place in dermatophagic caecilian species.

### Relationship with Humans

It is possible that a small amount of Congo caecilians is circulating in the pet trade and captivity is likely the only interaction that humans have with this animal.

## In Captivity

Aside from being kept as an exotic pet presumably, the Congo caecilian cannot be found in any legitimate zoological institute.

## Sources

* Herpele squalostoma | Wikipedia - https://en.wikipedia.org/wiki/Herpele\_squalostoma
* IUCN Red List of Threatened Species - https://www.iucnredlist.org/species/59565/16958011
* Herpele squalostoma | Amphibia Web - https://amphibiaweb.org/cgi/amphib\_query?where-scientific\_name=Herpele+squalostoma&rel-scientific\_name=contains&include\_synonymies=Yes