Geographic Range
Hyperolius marmoratus
is widely distributed in sub-Saharan Africa.
Habitat
Hyperolius marmoratus
is found in savannas and open bush along water sources such as rivers and streams,
as well as in lowlands that contain temporary pools during the rainy season.
- Habitat Regions
- tropical
- terrestrial
- freshwater
- Terrestrial Biomes
- savanna or grassland
- Aquatic Biomes
- rivers and streams
- temporary pools
- Other Habitat Features
- riparian
Physical Description
Hyperolius marmoratus
is small to medium in size, the male reaching 43mm in length. The side of its snout
is curved and the head width is 32-38% of its body length. The toes end in toe pads
that enable the frog to climb up stems of grass and reeds. They have an enormous
variety of brightly colored markings, with a profusion of stripes, spots, or stippling.
Currently, populations are grouped by shared color patterns into subspecies. Some
may be pale brown with darker spots or striped with lighter and darker brown. Others
may be striped with thick bands of black and white with a yellow stripe running down
the center. While, still others have red-brown spots on a light background. There
are many variations known.
- Other Physical Features
- ectothermic
- bilateral symmetry
- polymorphic
- Sexual Dimorphism
- sexes alike
Development
Hyperolius marmoratus
tadpoles hatch in less than a week and develop into small froglets within 2 months.
Tadpoles may grow to be 44mm in length. They are brown with speckled fins, and have
tails that end in a sharp point tipped with black. The tadpoles are bottom dwellers,
and prefer shallow, grassy pools. In captivity, metamorphosis takes 64-100 days.
The adult color phase develops when the frog reaches sexual maturity. The identification
of
Hyperolius marmoratus
depends largely on color pattern.
- Development - Life Cycle
- metamorphosis
Reproduction
Males establish small calling territories in ponds in order to breed. Elevated calling
sites are defended through intense kicking bouts against any male intruders.
Hyperolius marmoratus
females approach males in breeding ponds and initiate amplexus.
- Mating System
- polyandrous
- polygynous
This lasts for several hours making it possible for a male to mate with only one female
each night. Fertilization is external during the period of egg laying. A
Hyperolius marmoratus
clutch consists of 150-600 small eggs that are between 1.3-1.5mm in diameter, and
are within 2.5mm capsules. The eggs are laid in clumps of about 20, attached to underwater
vegetation, during the rainy season. They are pale yellow with a dark brown end,
although some have also been reported to be blue-green. In captivity, females are
reported to produce eggs every 2 or 3 weeks for up to 14 months or longer, once they
reach sexual maturity. In the field this may be variable depending on the weather.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- oviparous
Neither sex provides parental care.
- Parental Investment
- no parental involvement
-
pre-fertilization
- provisioning
-
protecting
- female
Lifespan/Longevity
In captivity
Hyperolius marmoratus
can live at least 4 years 9 months.
Behavior
Hyperolius marmoratus
is highly terrestrial and returns to water only to breed. They spend much of the
day sitting motionless on reeds and other waterside plants, while at night they become
more active and the males begin to call. During the heart of the dry season
H. marmoratus
entirely suppresses feeding, and its survival time depends both on energy reserves
and on its ability to minimize evaporative water loss.
Hyperolius marmoratus
spends much time exposed to the bright sun, putting it at risk from drying out. Yet
it still has a very low rate of water loss through the skin compared with other frogs.
Water is conserved by
H. marmoratus
in three ways. First, it has a "water balance" response in which it reduces activity
and rests in a water-conserving posture that minimizes surface exposure. During the
dry season it remains motionless on a single leaf throughout the day. It also aestivates,
which is a special form of dry season "hibernation." This slows down its metabolism
to 50% of its normal resting rate. Also during the dry season, especially during
high temperatures,
H. marmoratus
is white and therefore reflects sunlight. This color comes from the food that
H. marmoratus
consumes. Food wastes are converted into substances called purines. Small purine
platelets arranged parallel to the surface are part of the pigment cells, or iridiophores,
of the skin. These crystals act as interference reflectors, and reduce the heat load
by reflecting sunlight. Lastly,
H. marmoratus
becomes completely anuric when dehydrated. Because of this it is able to store water
in the bladder which can be used later for cooling when conditions become harsh.
Above very high temperatures it makes use of this water by releasing it through the
skin to evaporate and cool itself. Also,
H. marmoratus
has an accelerated water uptake, which can extend the survival period when dewfall
or very short and light occasional rain showers supply a few drops of water at irregular
intervals.
- Key Behaviors
- saltatorial
- nocturnal
- motile
- sedentary
- aestivation
- solitary
- territorial
Home Range
There is no information available on home range in this frog species.
Communication and Perception
Hyperolius marmoratus
has an impressive vocal capacity. The male calls from vegetation around bodies of
water. The call is a short whistle, only about 0.1 seconds long and has a frequency
ranging from 2.8 to 3.1 kHz. The vocal sac of
H. marmoratus
is very large. This amplifies his call, making it very loud. Two males may call simultaneously,
alternating with a third male. The call helps to maintain male spacing to a minimum
of about 50 cm. Females prefer to select an isolated male as opposed to a male calling
close to another male, as well as a male that is near to the female's release site.
Females are also attracted to high call rates and greater intensities. Females select
the male with the loudest call, so long as there is a noticeable difference between
the calls of that area. It is speculated that females choose conspicuous males in
order to reduce search time when under the risk of predation in the chorus. It has
been found that chorus tenure duration has the most significant influence on mating
success. Because calling is energetically expensive to
H. marmoratus
, by mating, males are able to conserve energy, which enables them to attend the breeding
site more frequently and to call more energetically. Males will also return on successive
evenings to exactly the same calling site.
Touch is used to initiate amplexus. These frogs also perceive the environment with their keen eyesight, attuned to perceiving motion.
- Perception Channels
- visual
- tactile
- acoustic
- vibrations
- chemical
Food Habits
Hyperolius marmoratus
feeds on a variety of small insects.
- Primary Diet
- carnivore
- Animal Foods
- insects
- terrestrial non-insect arthropods
Predation
Hyperolius marmoratus
adults rely on their agility and ability to leap great distances to escape from danger.
They also have red skin on the inside of the thighs and the side of the belly, which
functions as a startle mechanism, because it is only visible when the animal jumps.
Ecosystem Roles
Hyperolius marmoratus is prey to many different species of animals in its ecosystem.
Economic Importance for Humans: Positive
Hyperolius marmoratus
is known to be a predator of the important citrus pest, the citrus psylla (
Diaphorina citri
).
- Positive Impacts
- controls pest population
Economic Importance for Humans: Negative
There are no known adverse effects of these frogs on humans.
Conservation Status
These frogs are widespread and not currently considered threatened. Local populations may be threatened by water diversions, habitat disruption, and pesticide or herbicide use.
Additional Links
Contributors
Tanya Dewey (editor), Animal Diversity Web.
Jessica High (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.
- Ethiopian
-
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- freshwater
-
mainly lives in water that is not salty.
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
- riparian
-
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- polymorphic
-
"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.
- polyandrous
-
Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).
- polygynous
-
having more than one female as a mate at one time
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- external fertilization
-
fertilization takes place outside the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- saltatorial
-
specialized for leaping or bounding locomotion; jumps or hops.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- territorial
-
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- duets
-
to jointly display, usually with sounds in a highly coordinated fashion, at the same time as one other individual of the same species, often a mate
- choruses
-
to jointly display, usually with sounds, at the same time as two or more other individuals of the same or different species
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- vibrations
-
movements of a hard surface that are produced by animals as signals to others
- chemical
-
uses smells or other chemicals to communicate
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- metamorphosis
-
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
References
Channing, A. 2001. Amphibians of Central and Southern Africa . Ithaca and London: Comstock Publishing Associates - Cornell University Press.
Dyson, M., S. Henzi, T. Halliday, L. Barrett. 1998. Success breeds success in mating male reed frogs (Hyperolius marmoratus). The Royal Society of London , 265: 1417-1420.
Grafe, T. 1997. Costs and benefits of mate choice in the lek-breeding reed frog, Hyperolius marmoratus. Animal Behavior , 53: 1103-1117.
Schmuck, R., W. Geise, K. Linsenmair. 1994. Life cycle strategies and physiological adjusments of reedfrog tadpoles (Amphibia, anura, hyperoliidae) in relation to environmental conditions. Copeia , 4: 996-1007.
Schmuck, R., K. Linsenmair. 1997. Regulation of body water balance in reedfrogs (superspecies Hyperolius viridiflavus and Hyperolius marmoratus: Amphibia, anura, hypeoliidae) living in unpredictably varying savannah environments. Comparative Biochemistry and Physiology , 118A (4): 1335-1352.
2001. "Survival Online" (On-line). Accessed March 18, 2002 at http://www.tiscali.co.uk/reference/nature/survivalonline/reedfrog.html .
2002. "Travel Africa Online" (On-line). Accessed 11/14/05 at http://www.travelafricamag.com/content/view/711/72/ .