Centrolenella fleischmanni is a small and arboreal frog that lives in lowland and mid-elevation forests of Central and South America[1]. This species of frog has skin that reflects near-infrared light which helps them to avoid predation[2]. Their calling site choice is largely affected by the surrounding vegetation[3]. Males start calling at dusk and decline as the night progresses[1]. C. fleischmanni is a type of frog where the male puts effort at the stage of egg attendance[4].

Centrolenella fleischmanni

Description edit

C. fleischmanni are small and arboreal frogs that lives in lowland and mid-elevation forests of Central and South America. They call during the rainy season[1]. They have green skin that reflects visible light typically at 400 nm to 700 nm[2].

Distribution edit

Centrolenella fleischmanni inhabit forests up to 2,000 meters above sea level in Central and South America[1]. They have a very wide geographic distribution from Mexico to Ecuador and Suriname and are one of the most altitudinal species of their genus (approximately sea level to above 1600 m)[4].

Vegetation affects the choice of calling site edit

According to some researchers, the calling site of male C. Fleischmanni is sometimes found on plants with broad leaves that overhang rivers, and sometimes is found on the ventral side of horizontal (or near horizontal) leaves. These two different locations of calling sites have a large difference in how the vegetation will affect the propagation of sound. Whether male frogs choose their own calling sites because of the acoustic properties of that calling site has not yet been explained, but related studies have clarified the relationship between vegetation and sound propagation. In fact, the difference in acoustic properties of the calling sites due to the physical characteristics of the environment indeed affects the success rate of courtship and territory protection. Frogs are not directional sound sources, but vegetation and many other environmental factors helps to form directional, beaming-like calls. Research has shown that frogs who have their calling site more than 0.6 meters above the ground have an increased rate of attracting mates than their counterparts below 0.6 meters. A plausible explanation for this is that higher areas are relatively more open, while lower calling sites tend to have more complex vegetation coverage, thus causing the call to attenuate. By measuring and comparing the Sound Pressure Levels (SPL) of C. fleischmann, a study elucidates the effect of vegetation on sound intensity and directionality. The results of the experiment showed that calling on the leaves did not bring any directional consistency. Males on large leaves had a louder sound from the back, while males on small leaves had a significantly louder sound from the front. The pattern on the underside of the leaves was more consistent: at 50 and 100 cm, the sound in the front was always louder than that from the back, regardless of leaf size. The reason that calling below the leaf results in a directional sound in front is unclear, but it is presumed to be the effect of the angle between the frog's body and the leaf surface. The propagation of sound, on the other hand, is apparently attenuated by vegetation[3].

Home range and territoriality edit

Male C. fleischmanni do not persist in their territory for long. Most males were found to stay in the same territory for about 10 nights, and some for more than 15 to 20 days, generally falling within the range of 1 to 18 days. And they rarely defend their territory by overt aggression. The new territory will usually be within two meters of the original territory but occasionally as far as five meters.

There will usually be up to five clusters of eggs in a single territory. Males who occupy very large leaves usually stay on the same leaf after eggs are laid and continue to attract other females; males that occupy the small leaves commonly move to another leaf on the same plant.

A common calling site for males is observed to be the undersurfaces of broad-leaved plants such as Dieffenbachia, or shrubs, ground bromeliads, and epiphytes on tree trunks, all of which are around 0.5 to 10 meters above the ground. Male also tries to find a place over the main stream channel, thus the calling site is usually close to the water, about 0 to 6 meters[5].

Reproduction and life cycle edit

Males defend their call sites and attract females. Male C. fleischmann call under the leaves and their calling usually begins at dusk, sometimes lasts until the dawn, and decreases calling as the night progresses. However, whenever males are participating in amplexus or attending eggs, they do not call[1]. While conspicuous vocalization helps male C. fleischmanni attract female individuals, it also increases their risk of exposure to predators[6]. From May to September, which is the breeding season of the C. fleischmanii frogs, females Centrolenidae fleischmann will constantly appear for mating. Female C. fleischmanns stop moving around vegetation close to calling male frogs. The female will then gently push on the male from the side and crawl under them, after that the male frog will clasp the female frog. That is the process of amplexus. Female C. fleischmanni prefer to lay their eggs on overhanging leaves by the river. The hatched tadpoles will fall into the river and stay in the silt at the bottom of the river[1] . Full gestation time, from egg laying to hatching, spans approximately 8 to 21 days. All the tadpoles in the clutch hatch within a day, but the tadpoles disappear within 2-3 days. The development of tadpoles will show a series of color changes. They go from yellow to orange to red, and hatching occurs almost exclusively in the orange or red stage. The yellow tadpoles may not be able to survive on their own, so the disappearance of the yellow tadpoles is most likely due to predators. However, when the tadpoles reached the orange stage on the eighth and ninth days, they will have enough ability to survive on their own[5].

Mating edit

Female frogs lay and deposit eggs close to the calling site so they can be defended by males. Male attend to eggs by returning to the same calling site in succession and fertilizing the eggs of several females.

If it’s a dry night, the entire population will become inactive. The advertisement call of males are peeps between 4300 o 5300 Hz, around 0.1 seconds long, and 4 to 10 calls per minute, with no dominant frequency. A single peep will last about 0.4 seconds, which is then termed as a mew when a male discovers other frogs in his territory; this is called the encounter call.

Male-male interaction edit

Most of the time, calls are from the resident frog instead of the insider frog; physical contacts are uncommon.

Male-female interaction edit

During the process of amplexus, males are stationary for the most of the time, which means they rarely start the amplexus. Then, “When entering the calling site of a male individual, a female will move up, down, and to the edge of the site while staring at the ground when the female comes into the calling site of that male individual, afterward, she will continue to circle the male in a low, flattened posture. When the male detects the existence of the female, generally different types of calls will be given during the courtship. First, they will start with a mew interspersed with a shorter mew than the usual mew, then is the 0.1 second long chip call when male and female come to the surface of a leaf. If another female approaches, females won’t interaction with each other. The late female will stop and find another calling male if the original male clasps the first female.

Parental care edit

Males’ involvement in parental care occurs at the stage of egg attendance. They assume a ventral contact brooding and rotate and manipulate the jelly of the clutch. Males manipulate the eggs in several ways, such as grasping the clutch from near the periphery and using their four limbs to pull the clutch and then release it. Males also use their hindlimbs to stoke the jelly[4].

Enemies edit

A fringe-lipped bat, Trachops cirrhosus, is known to focus attention on those calling C. fleischmanni frogs[6]. Some other organisms were also found to predate on C. fleischmanni. Prionostemma frontale, specie of Phalangids, found to predate centrolenella fleischmannni on the prehatching stages of the frogs. P. frontale will use their chelicerae to slice the jelly that contains the pre-hatch. P. frontale will then take out the embryos or eggs from the jelly while the post-hatching capsule looks no different and not have been disturbed from the pre-hatching jelly. Moreover, Cupiennus was observed to be a predator of C. fleischmanni as well[7].

Protective coloration edit

The study found C. fleischmanni reflecting near-infrared rays from 700 to 900 nm under infrared color photography detection despite their own green skin reflects visible light typically at 400 to 700 nm. Therefore, when they rest on photosynthetic leaf surfaces that also reflect infrared light, they are virtually indistinguishable both in visible light and near-infrared light ranges. Two functions were thought to be the reason for this discovery while hasn't been fully studied. One is that these skin aid frog thermoregulation. Frogs keep their bodies warm because skin absorption causes protons of these wavelengths (near-infrared wavelengths) to lose energy as heat, in other words, heat is absorbed by the skin. The second possibility is an improvement of cryptic coloration developed to avoid those predators with infrared receptors. Some animals, such as birds and snakes, have a presence in their bodies that helps them increase their sensitivity to near-infrared rays at night. If the frog's skin simply reflects visible green light, then even green frogs on green leaves could still be spotted by these particular predators[2].

At the same time, purple pigments were also found in their chromatophore, but the main function is still unclear[2].

Interactions with human and livestock edit

Artificial affections on environmental interventions may promote the growth of algae and bacteria in streams. C. fleischmanni larvae readily feed on this resource[4].

References edit

  1. ^ a b c d e f Jacobson, Susan K. (1985). "Reproductive Behavior and Male Mating Success in Two Species of Glass Frogs (Centrolenidae)". Herpetologica. 41 (4): 396–404. ISSN 0018-0831.
  2. ^ a b c d Schwalm, Patricia A.; Starrett, Priscilla H.; McDiarmid, Roy W. (1977-06-10). "Infrared Reflectance in Leaf-Sitting Neotropical Frogs". Science. 196 (4295): 1225–1226. doi:10.1126/science.860137. ISSN 0036-8075.
  3. ^ a b Wells, Kentwood D.; Schwartz, Joshua J. (1982). "The Effect of Vegetation on the Propagation of Calls in the Neotropical Frog Centrolenella fleischmanni". Herpetologica. 38 (4): 449–455. ISSN 0018-0831.
  4. ^ a b c d "A study of clutch attendance in the neotropical frog Centrolenella fleischmanni (Anura: Centrolenidae) - ProQuest". www.proquest.com. Retrieved 2022-10-13.
  5. ^ a b Greer, Beverly J.; Wells, Kentwood D. (1980). "Territorial and Reproductive Behavior of the Tropical American Frog Centrolenella fleischmanni". Herpetologica. 36 (4): 318–326. ISSN 0018-0831.
  6. ^ a b Tuttle, Merlin D.; Ryan, Michael J. (1981-11-06). "Bat Predation and the Evolution of Frog Vocalizations in the Neotropics". Science. 214 (4521): 677–678. doi:10.1126/science.214.4521.677. ISSN 0036-8075.
  7. ^ Hayes, Marc P. (1983). "Predation on the Adults and Prehatching Stages of Glass Frogs (Centrolenidae)". Biotropica. 15 (1): 74–76. doi:10.2307/2388005. ISSN 0006-3606.