User:Reni.Akande/Taita African caecilian

Description
As stated above, Boulengerula taitana are caecilians, amphibians that are limbless and long; these amphibians’ skin is divided into ring shapes, giving the animal a similar appearance to that of an earthworm.

Hatchling B. taitanas are about 28mm in length and have an inadequately ossified axial and skull skeleton in contrast to other direct-developing species. Hatchling B. taitana also has weakly developed body musculature and external annulation, which negatively affects their mobility – essentially restricting it. When offspring are at the stage in their life where they become independent, they total about 86mm in length.

Compared to hatchlings, adult B. taitana are typically seen as predators, exhibiting two rows of pointed teeth in the premaxillary-maxillary parts of the jaw and vomer palatine in the dentary and splenial parts of the jaw, which have one to two distinct cusps. The monocuspid teeth of the B. taitana are the three or four of the most anterior teeth and the vomer palatine teeth. There is then the combination of noticeable labial cusps with a lingual cusp made up of two to three supplemental cusps that make up the rest of the teeth and are multicusped. These teeth are either more pointed and elongated or are shorter and blunter.

Habitat
B. taitana are found to occupy forest environments more than agricultural environments in east Africa. B. taitana has also been found to be longer in length when found in forest settings compared to agriculture settings – with forest B. taitana averaging 285.9 mm and agriculture B. taitana averaging 219.3mm. B. taitana are typically found only a couple centimeters into the soil beneath rotting logs and in the soil that gradually builds up around static rocks.

In this environment, B. taitana exhibit horizontal movements, which is demonstrated by them moving closer to parts of the soil that are closest to permanent water sources after the area dries out, then they move away after rainfall when the soil has become too moist. B. taitana is dependent on minimal moisture in the soil; this limits them, during drier periods, to soils near water bodies or deeper soils. In order to feed on their prey, B. taitana migrate to surface soil.

Geographic Distribution
Endemic to the Taita Hills of Kenya, the B. taitana is currently the only caecilian amphibian that inhabits this area. In the Taita Hills, the B. taitana are called “ming’ ori,” which is commonly used for earthworms. This miscalling heavily affects the misunderstanding of caecilians as earthworms. The B. taitana is commonly found in an agricultural social ecosystem or the forest.

Initially, the Taita Hills were mainly forest grounds, but now the area is primarily low-intensity, small-scale agricultural units, with the majority of this area not being cultivated. The climate of this area is described as seasonal precipitation that varies. Throughout the year, the rainfall is characterized as monsoonal, with April to October having wetter south-easterly monsoons; November to March has north-easterly monsoons that are drier.

Juvenile
Following the dentitional metamorphosis stage of development, B. taitana transitions into generalist predators. Their diet typically consists of social macrofauna, including termites, ants, and earthworms.

Adult
Adult B. taitana primarily eats termites, dipteran larvae, ants, antlions, slugs, thrips, centipedes, and earthworms. Still, it has been documented that B. taitana eats more termites and earthworms compared to the other macrofauna taxa they typically consume.

Fertilization
In B. taitana, fertilization takes place internally, making it a direct-developing oviparous caecilian, and the females of the species take responsibility for guarding their eggs. Cell proliferation and degeneration are functional and morphological changes of the oviducts that occur during the ovarian cycle and pregnancy to be where fertilization and early embryonic development occur.

The oviducts of B. taitana are more elongated and lie laterally to the ovaries and kidneys. The anterior part, which consists of the ostium, is located near the heart. The posterior part of the oviduct is stops at the cloaca. The oviduct is split and differentiated into three segments: anterior, middle, and posterior. Each segment comprises a serosa, mucosa, and a thin muscular layer. The folded section of the mucosal layer is sheathed in the pseudo-stratified epithelium and reinforced by the tissue of the lamina propria.

The sexual cycle is annual and is divided into three periods: from September to October is preparation, from November to February is ovulation, and from March to August is a rest period. Between March and August, the oviduct diameter of the B. taitana varied from 120-170μm. The epithelium, which is somewhat developed, borders a narrow lumen. At the same time, the lamina propria is narrow and contains very little blood vessels. At this point, the para recta (the anterior segment) has a limited amount of shallow crypts, and the surface epithelium contains a multitude of clusters of ciliated and secretory cells. The par utera (the posterior segment) section of the oviduct is the most folded at this time.

From September to October, the environment of the oviduct becomes more complex and more extended. At this time, the diameter of the lumen increases, the thickness of the lamina propria increases, and the epithelium are at its thickest. The pars recta secretory cells increase in size, and there are significant developments in the ciliature and secretory cells of the pars convolute (the middle segment). In the cytoplasm of ciliated cells, acidic carbohydrates are also detected.

These changes allow the oviduct of the B. taitana to be a perfect environment for ovulation and fertilization. At the end of ovulation in February, the para recta contain very few ciliated cells and a large number of glandular cells. The pars convolute contains secretory, goblet, and ciliated cells, and the par utera only has one type of glandular cell. The epithelial mucosa is more secretory at this time, and there is a greater abundance of cilia cells.

Brood Size
Broods of B. taitana range from two to nine young. They have the most petite clutch sizes compared to all other caecilians. For pregnant females, smaller clutch sizes allow them to continuously burrow within rigid substrates and feed on prey due to the minimal changes to the thin body.

Life Cycle
Another year after they become subadults, they mature into adults, reaching a size of 240mm or more.

Site Selection for Egg Laying
The eggs of B. taitana are laid in terrestrial chambers constructed by females, negating development through an aquatic larval stage. Prior to or following the hatching of their eggs, Imothers typically occupy areas that place them close to other nesting females. By doing so, females increase their own and their offspring, chances of social interactions, and the prospect of communal breeding.

Feeding Young
B. taitana is an oviparous caecilian, and there is a parent-offspring transfer of nutrients after birth. B. taitana have young children born in an undeveloped state, thus requiring them to need feeding and care by the parents. The dentition of offspring includes ‘fetal-like’ teeth, which they use to peel and eat the modified skin of their mothers after birth. The peculiar dentition of dermatophagous (skin feeding) may be the result of a pre-adaptation to fetal viviparous caecilians eating the oviduct lining of their mothers. After their birth, the young position themselves on different parts of their mother’s bodies and repeatedly use their lower jaws to lift and peel the outer lays of the skin, which are rich in lipids. Within one week of care, young B. taitana substantially increase in total length, averaging about 1 mm per day. This is because the ingested skin provides a copious amount of nutrients to the offspring. At the same time, weight loss is exhibited by the mother, which is consistent with continuous feeding of their offspring, and imposes a high cost onto the mother.

The skin color of nurturing mothers is also considerably lighter than other males and males due to the differences in the composition at the cellular and tissue level. This difference is most likely due to the role of skin in nutrition for the young. The stratum corneum, the outermost layer of the epidermis, consists of flattened, keratinized cells. The cells of brooding females are lengthy and full of vesicles, and, as a result, the epidermis is double the thickness of non-brooding females. Brooding females are shown to have lower amounts of body fat and negatively impacted body conditions, with these conditions decreasing significantly throughout the time of caring for their young.

Beneficial Interspecific Relationships
In a study conducted, it has been shown that it is typical for two fathers to sire a single litter. There is also a high probability of offspring not being cared for by their biological mothers, which showcases an example of alloparenting.

Respiration
B. taitana are fossorial species, meaning their habitat consists of burrowing into moist and hard packed soil. Due to this, B. taitana often encounters hypercarbic and hypoxic conditions, which showcases that blood respiratory properties may be a result of adaptive features to its environment and behavior. Oxygen uptake levels of B. taitana are significantly higher than those of other caecilians, but they fall within the ranges of other amphibians. The O2 capacity of B. taitana is 14% volume, which is very high. Compared to other amphibians, the erythrocytes are smaller in size, their red cell count is significantly higher, and their oxygen affinity of the whole is higher.