Animal Diversity Web

Ge­o­graphic Range

Hy­per­olius mar­mora­tus is widely dis­trib­uted in sub-Sa­ha­ran Africa. (Chan­ning, 2001)

• Biogeographic Regions
• ethiopian
  • native

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. (Chan­ning, 2001)

• 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. ("Sur­vival On­line", 2001; Chan­ning, 2001)

• Other Physical Features
• ectothermic
• bilateral symmetry
• polymorphic

• Sexual Dimorphism
• sexes alike

• Range length

  43 (high) mm

  1.69 (high) in

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. (Chan­ning, 2001)

• 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. (Chan­ning, 2001)

• 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. ("Sur­vival On­line", 2001; "Travel Africa On­line", 2002; Chan­ning, 2001; Grafe, 1997; Schmuck, et al., 1994)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • external
• oviparous

• Breeding interval

  Females may produce eggs every 2 to 3 weeks.

• Breeding season

  Breeding seasons last from the first rains of spring to late summer.

• Range number of offspring

  150 to 650

• Average number of offspring

  300-400

• Average time to hatching

  5 days

Nei­ther sex pro­vides parental care. (Chan­ning, 2001)

• Parental Investment
• no parental involvement
• pre-fertilization
  • provisioning
  • protecting
    • female

Lifes­pan/Longevity

In cap­tiv­ity Hy­per­olius mar­mora­tus can live at least 4 years 9 months. (Chan­ning, 2001)

• Typical lifespan
  Status: captivity

  4.75 (high) years

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. ("Sur­vival On­line", 2001; Grafe, 1997; Schmuck and Lin­sen­mair, 1997)

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. (Chan­ning, 2001; Schmuck and Lin­sen­mair, 1997)

• 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. ("Travel Africa On­line", 2002; Chan­ning, 2001; Dyson, et al., 1998; Grafe, 1997)

Touch is used to ini­ti­ate am­plexus. These frogs also per­ceive the en­vi­ron­ment with their keen eye­sight, at­tuned to per­ceiv­ing mo­tion.

• Communication Channels
• tactile
• acoustic

• Other Communication Modes
• duets
• choruses

• Perception Channels
• visual
• tactile
• acoustic
• vibrations
• chemical

Food Habits

Hy­per­olius mar­mora­tus feeds on a va­ri­ety of small in­sects. (Chan­ning, 2001)

• Primary Diet
• carnivore
  • insectivore

• 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. ("Sur­vival On­line", 2001; "Travel Africa On­line", 2002; Chan­ning, 2001; Grafe, 1997)

• Known Predators

  • frog-eating bats (Nycteris grandis)
  • Angolan green snakes (Philothamnus angolensis)
  • herald or red-lipped snakes (Crotaphopeltis hotamboeia)
  • brown water snakes (Lycodonomorphus rufulus)
  • fishing spiders (Araneae)
  • young crocodiles (Crocodylus)
  • predatory birds, such as kingfishers (Alcedinidae)
  • tree frogs (Leptopelis)
  • red-legged kassina (Kassina maculata)

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). (Chan­ning, 2001)

• 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.

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  No special status

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.

Ref­er­ences

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/​.

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.