AMPHIBIAWEB
Morerella cyanophthalma
family: Hyperoliidae

Country distribution from AmphibiaWeb's database: Cote d'Ivoire

View distribution map using BerkeleyMapper.


Conservation Status (definitions)
IUCN (Red List) Status
CITES
Other International Status None
National Status None
Regional Status None

   

From the Encyclopedia of Life account:

Etymology

The genus is dedicated to Jean-Jacques Morère who first discovered these frogs. The specific name is based on the Greek 'cyano' meaning blue and 'ophthalmos' meaning eyes, referring to the bright blue eyes of the females.


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Summary

This monotypic specis has a slender body, large protruding eyes, a horizontal, oval pupil, and a small but distinct tympanum. Males exhibit a a medium sized, medioposterior gular gland, without thin dilatable skin beneath and around the gland, and minute spinosities on the back and on limbs.


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Distribution

This species is known from a few sites within Banco National Park, Ivory Coast. Additional frogs possibly conspecific with the new species have been recorded in the Azagny National Park, 100 km west of Abidjan. A similar looking frog, although completely yellow, was photographed in southern Taï National Park, 350 km from the type locality (Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Morphology

This is medium-sized tree-frog with slender body, comparatively flat head, slightly pointed snout, and a horizontally oval pupil. Large protruding eyes are approximately same size as interorbital distance. Tympanum is small but distinct andreaches only about one third of eye diameter. Naris much closer to snout tip. Loreal region is very slightly convex, and canthus rostralis is rounded. Upper mandible has minute teeth; prevomerine teeth are absent. Tongue is heart shaped, slightly notched posteriorly, more than two thirds free. Ventral surfaces are granular. Femur and tibia length reach about half SUL; foot incl. longest toe reaches about two thirds of SUL. Finger and toe tips are enlarged to round discs. Finger formula is as follows: 1<2<4<3. Only traces of webbing between fingers. One subarticular tubercle on each of fingers 1, 2 and 3, and 2 subarticular tubercles on finger 3. Small plamar tubercle is present. Toe formula is as follows: 1<2<3=5>4. Toe 2, 3 and 5 have two subarticular tubercles, toe one with one tubercle, toe 4 with three tubercles. Small elongate inner metatarsal tubercle present. Lower side of feet densely beset with flattened tubercles. Webbing formula is as follows: 1 (1), 2 i/e (1-0.5), 3 i/e ( 1-0.5), 4 i/e (1), 5 (0.3). Males with medium sized, medioposterior gular gland a, stretching from middle of the throat onto anterior part of breast; no dilatable skin is present beneath or around gular gland. Small spines are present on back and extremities of males; largest spines densely on lower and outer part of hind feet (Rödel et al., 2009).

The sexes are dichromatic. The females have a uniform brownish red, red-beige or bright orange-red dorsum, including extremities and toe and finger discs. Their throat and belly is colored whitish yellow to orange, the ventral parts of hind limbs are bright yellow or orange. The iris of females is grayish blue to bright blue. The iris of males varies from porcelain white in bright sunlight to grayish or yellowish brown in darker surroundings. Male dorsal surfaces including extremities vary between dark brown or almost black, to clear beige. Males’ backs can be either uniform or covered with smaller blackish and/or yellowish spots. In daytime retreats some males change to almost female orange coloration. At night the basic color of males changes to a clear yellow. Males almost always have dark canthal stripes (not visible in very dark individuals), that sometimes is bordered dorsally by a narrow yellowish stripe. The latter often continues behind the eyes as a dorsolateral band, which however, almost always breaks into spots and vanishes just dorsal to the forearm origin. Males’ throats and gular glands are whitish yellow to yellow. The bellies are white, rarely yellow, the lower surfaces of hind limbs are dark grey, in rare cases orange like in females. Breasts and the ventral parts of males’ forearms are flesh-colored, possibly indicating pectoral and humeral glands. Toe and finger tips exhibit the coloration of the back or are grey. In preservation most males are identical to the holotype. Dorsolateral bands remain visible in preservation, few males have almost uniform brown backs. Females in preservation are uniform brown dorsally and uniform clear pinkish ventrally or almost uniform clear beige with minute small black points (Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Osteology

Skull slightly longer than broad; snout rounded in dorsal and ventral view; surfaces of skull almost smooth; nasals triangular, not in contact with each other, canthal area rounded; sphenethmoid not visible dorsally; ventroanterior portion of sphenethmoid unfused, consisting of two elements; frontoparietal large and rectangular; quadratojugal narrow, contacts maxilla anteriorly; maxilla and premaxilla with minute teeth, prevomerine teeth absent; columella present; thyrohyal bones on cartilaginous stalks; posterolateral process of hyoid absent; anteriormost portion of the anterior horn of hyoid absent, hence horn composed of an anteromedial and a lateral process (staining and microtomography revealed slight differences in the shape of the lateral element of the anterior horn); vertebrae diplasiocoelous; neural arches non-imbricate, not completely roofing the spinal canal; transverse processes of eighth vertebra not angled markedly forward; pectoral girdle firmisternal; medial margins of coracoids entire; omosternum greatly forked, space between arms more than twice width of one arm; sternum ratio of caudal margin to anterior margin is 2.3; sternum completely ossified (microtomography results showed a more compressed sternum compared to staining and clearing); terminal phalanges slender, slightly curved and peniform; intercalary elements between ultimate and penultimate phalanges of fingers and toes present and completely mineralized (Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Size

Both sexes may reach a maximum SUL of 34–35 mm. However, adult males were significantly smaller than adult females (Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Habitat and Ecology

The type locality is situated in the centre of Banco National Park, and the frogs were collected from a water filled rill (1 m width, about 50 cm deep; clear; slow-flowing water; submerged vegetation) that is situated between a clearing and swampy rainforest (Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Activity and Special Behaviors

This is a nocturnal tree-frog, active after dark. Males and females sit at heights of 0.4–1.8 m on leaves of herbs and shrubs in swampy areas close to creeks and rivers. During daytime they sometimes hide in the leaf litter, but usually between leaves of herbs and shrubs. In the lab (12/12 light cycle) the frogs spend the day well hidden in leaf axils (Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Metamorphosis

Tadpoles hatched after 8–10 days with a large, bulging yolk sac, external gills, mouth still closed. One day after hatching tadpoles were free swimming. The mouth of eight day old tadpoles started opening; upper and lower jaw sheets became visible as narrow arches. The tadpoles still had external gills. Tadpoles lost the external gills after eleven days when they started feeding. Further development in captivity was very slow and most tadpoles died of unknown reasons. Embryos only developed and hatched successfully in slightly acid water (pH 6–6.5) and very low conductivity. Developmental time under natural conditions is unknown (Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Advertisement Call

Calling peaked in the field between 20:00 and 21:00 hours. After 01:00 hours in the morning, calls are
uttered only very rarely. On very hot and humid days, males also called during daytime. The advertisement call was a tonal note typically repeated 2–3 times (Fig. 7). Calls were short in duration (83 ± 7 ms, range 76–90 ms, N= 3). Intervals between calls within a call group averaged 174 ± 8 ms (range = 122–236 ms, N= 3). Dominant frequency of calls was 2.40 ± 0.02 kHz (range = 2.38–2.41 kHz, N= 3; Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Reproduction

Most clutches seemed to have been deposited at night. Eggs were usually attached in groups to the dorsal surface of leaves or roots, mostly 2–15 cm above water (N> 10); in some eggs were attached to a root just below water surface (N= 2) or in the water (N= 2). Eggs that were covered with water did not develop. Frogs were observed sitting on the lower side of leaves just above the clutches, but it is uncertain whether this constitutes parental care. Egg numbers ranged from 30–144 eggs (x= 73.8 ± 39.3 sd; N= 8). The mean germ size of the black and white eggs was 1.53 mm (± 0.08 mm sd; N= 9). Mean size of the eggs with jelly was 4.69 mm (± 1.00 mm sd; N= 9; Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Tadpole morphology

Exotrophic, lentic tadpoles; Gosner stage 25–28 larvae with: body elongate ovoid in dorsal, slightly depressed in lateral view (Fig. 8), sides of body almost parallel; small eyes, positioned dorsolaterally; nares large, positioned dorsally, approximately equal distance to eyes and snout-tip; oral apparatus in anteroventral position; dorsal lip wide and smooth, with anterior gap of marginal papillae; ventral
lip with large, biserial marginal papillae; submarginal papillae absent; upper jaw sheath is a narrow smooth arc; lower jaw sheath u-shaped; labial tooth row formula in young stages just after hatching: 0/0; stage 25 tadpoles and older have a labial tooth row formula of 1/1+1:2; supra-angular labial teeth row on bulging lip; infra-angular labial teeth rows on separate dermal lobes (Fig. 8); few labial teeth unidenticulate (most on upper lip); most labial teeth multidenticulate (Fig. 8); vent tube dextral; spiracle sinistral; very long tail axis (>2 times body length); tail axis height almost equals height of dorsal fin; dorsal fin originates dorsal to tail body junction, highest point is anterior to mid point of tail; ventral fin narrower than tail axis, almost parallel to tail axis; tail tip rounded. Body clear brownish dorsally, a band stretching between eyes from tail body junction anteriorly to level of nares slightly clearer brown, bordered by reddish brown line, lateral and ventral body parts almost translucent; three pairs of silverish spots caudal to eyes, converging towards mid body; tail axis cream with a narrow dorsal brown stripe, tail fins hyaline (Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Growth

Freshly hatched tadpoles have very large yolk sacs; a body length of 2.3 mm and a total length of 5.6 mm. Shortly before metamorphosis (Gosner stages 37–41) tadpoles reach body lengths of 10.18–11.78 mm (x= 11.12 mm ± 0.67 sd; N= 4) and total lengths of 37.37–40.73 mm (x= 38.55 mm ± 1.58 sd; N= 4). Snout-urostyle length of froglets with four limbs and no or only short tails ranged from 9.75–13.31 mm (x= 11.45 mm ± 1.14 sd; N= 6; Rödel et al., 2009).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

IUCN Red List Category and Justification of Conservation Status

This species is not yet listed by the IUCN Red List (19 May 2010). According to the IUCN Red List categories and criteria this species should be considered Critically Endangered (Baillie et al. 2004). This categorization is based on the fact that the extent of occurrence is less than 100 km² and the area of occupancy is less than 10 km². A population decline, by habitat loss and/or reduced habitat quality, can be inferred by the close proximity to Abidjan. If the records from Azagny and/or Taï National Park would be conspecific with M. cyanophthalma sp. nov., the species’ status should be changed to Endangered or Vulnerable, respectively.


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/