Introduction
Correlophus ciliatus is commonly known as the Crested Gecko, New Caledonian Gecko, or Eyelash Gecko. They are little native Australian arboreal reptiles found in the Isle of Pines, Grand Terre, and New Caledonia Islands (Carpenter Nature Centre, 2020). The crested geckos got their name ”eyelash geckos” due to their distinctive spikes or crests running on their backs which resemble eyelashes. Its other scientific name is Rhacodactylus ciliatus (Brusso, 2020). These gecko species are rare to see in their natural habitats. However, they can be found in zoos and pet trade institutions. The crested gecko was once thought to be extinct (Brusso, 2020). However, their numbers gradually increased due to human care and breeding facilities in zoological institutions. I chose the study of the crested geckos as they were almost extinct, and I would want to bring awareness to this rare lizard and encourage conservation efforts to protect these endangered species. Crested geckos are not harmful to humans and can be kept as pets.
Physical Description
Crested geckos have a large triangular head, with two large eyes and two ear openings on either side of the head. Wild crested geckos have three distinct color morphs; no patterns, white fringes, and a tiger-like appearance. They have shiny reddish-brown scales covering the body with dark stripes at the back.
The average weight of an adult crested gecko is between 30 to 35g, and its mean size from snout to the tail tip is 8 inches or 20.3 centimeters (Carpenter Nature Centre, 2020). However, its coloring varies in different habitats ranging from a bright orange fading to a pale green color. Crested geckos appear dark when they are about to shed their skin. The animals have four limbs, with each limb having four fingers containing cilia which enables the C. ciliatus to maneuver smoothly on soft leave surfaces. The hair-like features on the fingers form an adhesive-like bond on surfaces. The geckos also have a prehensile tail that supports them when hanging on branches. Also, the tail provides balance as they jump. Crested geckos do not have eyelids, but each eye contains a clear protective membrane that covers their eyes. The difference between male and female crested geckos begins to show at 3-4 months old (Brusso, 2020). For the male, they develop an outer hemipenal bulge at the tail base near the vent. However, female crested geckos do not bulge but remain flat at their tail bases.
Life Cycle & Reproduction
The life cycle of crested gecko has the following stages egg, hatchling, juvenile, and adult. Crested geckos exhibit indeterminate growth. Studies show that temperature plays a significant role in determining the rate of development, the size of the offspring, and sex. The sex of crested geckos is dependent on external environmental factors and not genetics. Warm temperatures during the breeding season result in high numbers of males, while cold temperatures result in higher numbers of female geckos.
Reproduction
There has been limited research on crested geckos’ mating behavior in their natural habitat. However, controlled studies show that captive males fight violently in the same environment during the mating season. Consequently, researchers place multiple females in a controlled environment with a single male. During the mating period, a male gecko exhibits jerky movements as it moves closer to the females; an interested female remains still while the male climbs on her for copulation. The mating system for crested geckos is polygynous. Therefore, the male can mate with several females in the same environment.
The male species takes between 9 and 12 months to reach sexual maturity, while the females mature at 12 months (Schaefer et al., 2020). A female crested gecko begins to lay eggs 30 -40 days after copulation and lays around two eggs within 4 -6 weeks (Schaefer et al., 2020). Temperature affects the egg production process, with cooler months slowing the breeding process. Crested gecko females lay highly permeable eggs which absorb moisture during the incubation period for embryonic development. The reproduction of crested geckos is iteroparous; thus, many offspring are produced across multiple seasons. The eyelash gecko breeds throughout the year except when cooler temperatures halt the process. Crested geckos are oviparous; thus, their offspring develop outside the mother’s body.
The Sensory System
Crested geckos are nocturnal; therefore, they have adaptive features to maneuver dark environments. They have large eyes on either side of the head. They have vertical split pupils to regulate the light. Crested geckos do not have eyelids like other reptiles; thus, their eyes are always open. They have a clear membrane instead that protects the eye. The geckos use their tongues to clean the membrane off any dirt and moisturize it.
Ears: The crested gecko has large ear openings on either side of the head and is sensitive to slight movements and sounds. The ears also have a clear protective membrane.
Nose: Crested geckos have two tiny holes at their snouts to sense and smell in search of food.
Skin: Crested geckos have fine smooth scales that change color depending on physical environmental factors such as light, temperature, and humidity.
Energy: Crested geckos are animals that feed on fruits, nectar, and small insects. Young crested geckos require vitamin D3 and calcium for development and proper growth (Melanie et al., 2018). Calcium deficiencies in the animal could result in fatal metabolic bone diseases. Females easily suffer from calcium deficiency when laying eggs; therefore, they have endolymphatic sacs in their mouths to preserve calcium. Pet crested geckos can receive calcium supplements. Crested geckos do not eat for 3 – 5 days after hatching but feed on stored yoke (Brusso, 2020). After five days, the hatchling searches for food, feeding on insects, nectar, and fruits.
Habitat: The crested gecko’s natural habitat is in the southern rainforest of Grand Terre and the New Caledonian Island, with a precipitation level of 400cm per year. They thrive well in temperatures ranging from 22.2º-23.9ºC. The eyelash geckos remain on the ground under leaves to shield them from the sun’s heat in the daytime. However, they rise to less than 300 meters from the ground and remain on the forest canopies, searching for food at night. The crested gecko has many predators, such the dogs, rats, cats, snakes, other geckos, and little fire ants. However, the main threat to the crested gecko is the little fire ants introduced to the New Caledonian Island, which attack and bite in swarms.
The eyelash gecko protects itself through caudal autotomy, where it drops its tail when in danger to distract the predators. The tail moves for five minutes as the crested gecko escapes to safety. The animal has a fragmented tail segment that allows it to drop at certain sections when fleeing danger. However, it cannot grow its tail back after falling and remains a frog tail. The gecko has a vasoconstrictor mechanism that prevents the tail bleeding when shed. The crested gecko can also be domesticated as a pet. The greatest threat to crested geckos is habitat destruction through global warming. Human activities such as large-scale logging and mining destroy forests, posing a threat to the animals. Furthermore, the domestication of exotic animals has led to the international trading of crested geckos. Removal of these animals from their natural habitat can lead to extinction.
Conclusion
Correlophus ciliatus has its natural habitat on the New Caledonian island. It is a small arboreal lizard with a large triangular-shaped head with eyes on either side and small openings for ears. It has four limbs and a prehensile tail. The life cycle of a crested gecko includes the following stages egg, hatchling, juvenile then adult. Due to their docile behaviors, the crested geckos are good candidates for pets. There is limited research on the crested gecko behavior in its natural habitat. The crested gecko plays a critical role in the ecosystem as they are pollinators of fruiting plants. They also host amoebas and parasitic protozoans. The crested gecko’s prehensile tail contains extraordinary adhesive abilities capable of holding up to five times its weight (Griffing, et al., 2021).
References
Brusso, K. (2020). Rhacodactylus ciliatus Crested Gecko, Eyelash Gecko. Web.
Carpenter Nature Centre. (2020). Crested Gecko Correlophus ciliatus Natural History. Web.
Doody, J. S., Dinets, V., & Burghardt, G. M. (2021). The secret social lives of reptiles. JHU Press.
Griffing, A. H., Sanger, T. J., Epperlein, L., Bauer, A. M., Cobos, A., Higham, T. E.,… Gamble, T. (2021). And thereby hangs a tail: morphology, developmental patterns and biomechanics of the adhesive tails of crested geckos (Correlophus ciliatus). Proceedings of the Royal Society B – Biological Sciences. The Royal Society.
Jones, E. (2021). Crested Gecko Growth Chart and Development Stages. Web.
Melanie L, H., Amanda, P., Haya, S. N., Madison, S. P., & Eileen, U. M. (2018). Food preferences of crested geckos, Correlophus Ciliatus. The Ohio Journal of Science, 118(1), A30. Web.
Schaefer, M. A., Wetzel, H., Skalican, K., Johanson, S., & Loughman, Z. (2020). Dominance in Female Crested Geckos (Correlophus ciliates). Proceedings of the West Virginia Academy of Science, 92(1). Web.