Morerella cyanophthalma Rödel, Assemian, Kouamé, Tohé & Perret, 2009
Morere´s Blue-eyed Frog
|Species Description: Roedel M-O, Kosuch J, Grafe TU, Boistel R, Assemian NE, Kouame NG, Tohe B, Gourene G, Perret J-L, Henle K, Tafforeau P, Pollet N, Veith M 2009 A new tree-frog genus and species from Ivory Coast, West Africa (Amphibia: Anura: Hyperoliidae). Zootaxa 2044:23-45.|
The dorsal skin surface is granular and has tiny spines, that become larger and denser towards the lower and outer part of the hind limbs. The fingers and toe tips end in enlarged round disks and there are only traces of webbing between the fingers. The third finger is the largest, followed by the fourth, the second, and finally the first. Fingers 1, 2 and 4 have one subarticular tubercle, finger 3 has two subarticular tubercles, and there is one small palmar tubercle. The length of femur (14.3 mm) and tibia (15.7 mm) reach about half of the body length. The foot, including the longest toe, reaches about two-thirds of body length (21.2 mm). The toes have the following relative formula for length: 1 < 2 < 3 = 5 > 4. The first toe has one subarticular tubercle; the second, third and fifth toes have two subarticular tubercles; and the fourth toe has three subarticular tubercles. Additionally, there is a small elongated inner metatarsal tubercle. The webbing between the toes has the following formula: 1 (1), 2 i/e (1 - 0.5), 3 i/e (1 - 0.5), 4 i/e (1), 5 (0.3). The ventral body parts are granular, and the underside of the feet is densely covered with flattened tubercles (Rödel et al. 2009).
The genus is comprised of only one species. As per Channing and Rödel (2019), the species exhibits a distinct appearance, particularly in female specimens possessing a bright orange dorsal coloration and large protruding blue eyes that are characteristic and distinguishable from any other species. Genetic analysis of mitochondrial DNA (16S, 12S, and Cytochrome b) indicates that M. cyanophthalma is a novel species (and the genus Morerella) possessing unique morphological, biological, and anatomical features within the range of inter-generic differentiation of the Hyperoliidae family. For example, the oval pupils in M. cyanophthalma set it apart from members of the genera Acanthixalus, Afrixalus, Arlequinus, Callixalus, Kassina, Kassinula, Opisthothylax, Paracassina, Phlyctimantis, Semnodactylus, and Tachycnemis. Another example is the distinct, but small tympanum in M. cyanophthalma distinguish it from members of the Acanthixalus, Afrixalus, Callixalus, Chrysobatrachus, Hyperolius, and Opisthothylax, which either lack tympani or have indistinct tympani. For more distinguishing characters please see Rödel et al. (2009)
The male holotype in preservation presents a dorsum of dark reddish brown color adorned with irregular black spots on the back, forearms, and lower legs. The dorsal side of the thighs is uniformly reddish brown, while the lower anterior half displays uniform pinkish brown color, and the posterior half is covered with numerous dark spots. The ventral portion of the lower leg appears uniformly pinkish. The canthal stripes encircling the eye are dark, and the lips and throat exhibit whitish color with brown spots. The gular gland appears in a yellow-beige hue. The flanks have a pale brown color on the dorsal side and gradually transition to a whitish color on the ventral side. The belly area is white, whereas the fingertips and toes are darker than the hands or feet. Furthermore, the feet's underside is grayish (Rödel et al. 2009).
Live individuals exhibit sexual dichromatic coloration. Females display uniform reddish-brown, red-beige, or orange coloration on their back, including their extremities, fingers, and toes. The belly is pale yellow to orange and the back legs are light yellow or orange. Female eyes are grayish to bright blue. Males have a dark brown to light beige color on their back and legs, sometimes with small dark or yellow spots. During the day, some males may change to an orange color similar to a female, but at night they turn yellow. The male iris can change color depending on the amount of sunlight. During bright sunlight, the iris can be porcelain white, while with less sunlight it can be grayish or yellow brown (Rödel et al. 2009; Konan et al. 2016).
The species is morphologically consistent, but there is evidence of color variation. Soro et al. (2019) report a deviation from the type localities in Banco National Park within the Tanoé-Ehy swamp forest, where some females display grey iris and males display blue iris. In addition, juveniles exhibit body coloration ranging from beige to orange, which is typically seen in adults. Male advertisement calls varied slightly in frequency (2.5- 2.67 kHz) and note repetitions (2 - 8 times), but the sample size was limited to one male. Kpan et al. (2014) reported that certain females from the same region exhibited a reddish-brown iris.
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Cote d'Ivoire
The species is found in wetlands, subtropical/tropical swamp forests, and evergreen forests. Assemian et al. (2015) observes that Morerella cyanophthalma serves as an indicator species for closed canopy forests and wet habitats in the Banco National Forest. In the Tanoé-Ehy swamp forest, the habitat includes Raphia palms, as observed in the Azagny National Park (Kpan et al. 2014). The type locality of this species is a water-filled ditch located at the forest edge between a clearing and a swampy forest (Rödel et al. 2009).
Life History, Abundance, Activity, and Special Behaviors
During the day, these animals prefer hiding among the leaves of shrubs and herbs, and they are rarely seen on the ground (occasionally, they hide in leaf litter).
The eggs are black and white and have a diameter of approximately 1.5 millimeters. These eggs are laid on leaves or overhanging vegetation that is above stagnant water, such as ditches or swamps. The eggs are laid on the top of leaves, 2 - 15cm above the water. The clutch ranges from 30 - 144 eggs. Egg laying occurs at night when they are most active (Rödel et al. 2009).
Adults have been found sitting near the eggs on plants. It is currently unclear if this behavior is related to parental care (Rödel et al. 2009).
The tadpoles have a brownish dorsum and their sides and belly are almost clear. There is a brown band starting from the nostrils between the eyes, stretching towards the junction of the tail and body. A reddish-brown line outlines the band. Behind the eye, there are three silver spots that come together in the center of the body. The tail's musculature is cream white and has a skinny brown stripe on its back. The tail fins are clear (Rödel et al. 2009). It is unclear if this description is in life or preservative.
The tadpoles emerge 8 to 10 days after egg laying and drop into the water. They feed externally and grow in still water (Rödel et al. 2009).
Trends and Threats
Possible reasons for amphibian decline
General habitat alteration and loss
Phylogeny:Morerella cyanophthalma belongs to the family of African reed frogs (Hyperoliidae), although the phylogenetic relationships among the many genera within the family remain unresolved. According to Rödel et al. (2009), the Leptopelis/Astylosternus clade was found to be the sister clade to Hyperoliidae. A recent study by Portik and Blackburn (2016) utilized nuclear markers and found that Morerella, a genus within the Hyperoliidae, is grouped with Cryptothylax, which consists of reed frogs from Central African forests. This clade is strongly supported and is a sister group to all Hyperolius species and the monotypic genus Chlorolius.
Etymology:Morerella cyanophthalma was initially collected by Jean-Jacques Morère in 1970 in the Banco National Park, but remained unnamed till 2009. The genus was named after him and the epitheton cyanophthalma describes the blue eyes of the females (Rödel et al. 2009).
Channing, A., and Rödel, M. O. (2019). Field guide to the frogs & other amphibians of Africa. Penguin Random House South Africa.
Gosner, K. L. (1960). A simplified table for staging anuran embryos and larvae with notes on identification. Herpetologica, 16(3), 183-190. [link]
Konan, J. C. B. Y. N., Kouamé, N. G., Kouamé, A. M., Adepo-Gourène, B., and Rödel, M. O. (2016). New data from Morerella cyanophthalma (Anura: Hyperoliidae) in Azagny National Park, southern-central Ivory Coast. Herpetology Notes, 9, 59-65. [link]
Kpan, T. F., Adeba, P. J., Kouamé, N. G., Koné, I., Kouassi, K. P., and Rödel, M. O. (2014). The anuran fauna of a volunteer nature reserve: the Tanoé-Ehy swamp forests, south-eastern Ivory Coast, West Africa. Zoosystematics and Evolution, 90(2), 261-270. [link]
Portik, D. M., and Blackburn, D. C. (2016). The evolution of reproductive diversity in Afrobatrachia: A phylogenetic comparative analysis of an extensive radiation of African frogs. Evolution, 70(9), 2017–2032. [link]
Rödel, M. O., Kosuch, J., Grafe, T. U., Boistel, R., Assemian, N. E., Kouamé, N. G., Tohé, B., Gourène, G., Perret, J.L., Henle, K., Tafforeau, P., Pollet, N., and Veith, M. (2009). A new tree-frog genus and species from Ivory Coast, West Africa (Amphibia: Anura: Hyperoliidae). Zootaxa, 2044(1), 23-45. [link]
Soro, N., Kouamé, A. K., Kouamé, N. G., Adepo-Gourène, B. A., and Rödel, M. O. (2019). Morerella cyanophthalma (Anura: Hyperoliidae) in south-eastern Ivory Coast: Additional data and implications for the species’ conservation. Herpetology Notes, 12, 1215-1223. [link]
Tanoe-Ehy Forest. Forest Conservation Fund. Retrieved 16 November 2023 from https://www.fundforests.org/tanoeehy-forest
Originally submitted by: Carolin Dittrich (2023-11-27)
Description by: Carolin Dittrich (updated 2023-11-27)
Distribution by: Carolin Dittrich (updated 2023-11-27)
Life history by: Carolin Dittrich (updated 2023-11-27)
Larva by: Carolin Dittrich (updated 2023-11-27)
Trends and threats by: Carolin Dittrich (updated 2023-11-27)
Comments by: Carolin Dittrich (updated 2023-11-27)
Edited by: Ann T. Chang (2023-11-27)
Species Account Citation: AmphibiaWeb 2023 Morerella cyanophthalma: Morere´s Blue-eyed Frog <https://amphibiaweb.org/species/7278> University of California, Berkeley, CA, USA. Accessed Dec 6, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 6 Dec 2023.
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