Philippine Amphibians Lecture PDF

Philippine Amphibians Endemic Amphibian Areas  General Habits and Distribution Habitat: Major Habitat Preferences of Amphibians General Habit and Distribution In the Philippines: ◦ Order Anura and Order Gymnophiona are present ◦ Caecilians documented only in Palawan and Mindanao (Mt. Malinda...

Philippine Amphibians Endemic Amphibian Areas  General Habits and Distribution Habitat: Major Habitat Preferences of Amphibians General Habit and Distribution In the Philippines: ◦ Order Anura and Order Gymnophiona are present ◦ Caecilians documented only in Palawan and Mindanao (Mt. Malindang, Zamboanga Peninsula and Davao) ◦ Frogs and Toads constitutes the majority of Amphibians in the Philippines Philippine Caecilians Forest-dweller Shallow depths of humus soil and underneath rotting logs Altitudinal range from sea level to about 1000 masl Larvae were recorded from pool of mountain streams Philippine Anurans Habitat: ◦ Occupy a variety of habitats ◦ Areas with adequate plant cover and moisture, near human habitations, in cultivated areas, and in various microhabitats in forest Philippine frogs Arboreal in habit Tips of their fingers and toes are expanded and usually developed webs in hands and feet In tropical rain forest, exist in microhabitat such as aerial ferns, Pandanus, and some aroid plants Examples of species inhabiting both forest and cleared areas: ◦ Polypedates leucomystax, Kaloula conjuncta and Kaloula picta Frogs limited to open cultivated areas ◦ Fejervaria cancrivora, Fejervaria limnocharis, Hylarana erythraea Forest species adapted to man-made ecosystem: ◦ Platymantis dorsalis and Platymantis corrugatus Elevation: ◦ Ranges from sea level to 2,000 masl ◦ Ansonia and Rhacophorus Burrowers: ◦ Kaloula, Occidozyga Aquatic in habit ◦ Either stay in the water or are limited to the immediate vicinity of water ◦ Occidozyga laevis, Staurois natator, Barbourula busuangensis Aquatic arboreal species ◦ Posses enlarged digit tips ◦ Sanguirana everetti BREEDING SEASON Some have definite breeding season ◦ Rana cancrivora, Kaloula conjuncta Breed continuously throughout the year ◦ Rana erythraea, Ooeidozyga laevis Species with no definite breeding season ◦ Platymantis, Sanguirana everetti, Limnonectes leytensis LIFE HISTORIES Reproductive Modes ◦ Eggs and larvae in temporary ponds ◦ Eggs and larvae in pools of mt. streams and/or slow flowing streams ◦ Eggs in foam nest over temporary ponds or pools of mt. streams, larvae in ponds or pools ◦ Oviposition site unknown (probably over water-filled tree hole) ◦ Eggs and non-feeding larvae in small volumes of water collected in leaf axils in in Pandanus ◦ Eggs in leaf axils of birds nest ferns and Pandanus, direct development ◦ Eggs on soil, direct development ◦ Eggs in aerial ferns, direct development ◦ Eggs in leaf axils of screw pines, direct development  Pelophryne brevipes eggs of this species are laid in small volumes of water in leaf axils Tadpoles develop depending entirely upon the yolk for they do not feed due to lack of functional mouth parts Lack external gills instead used vascularized tail fins for respiration Platymantis spp. Eggs are laid in non-aquatic situations Development occurs entirely within the egg capsules Differences in the later development (Limb bud stage, limb paddle, and operculum stages, metamorphosis) Respire by means of the large abdominal sacs, and depend entirely upon the egg yolk for nutrition  Philautus same with Platymantis but differs in the respiration process Tail is enlarged and has wide fine that are liberally supplied with blood vessel Longevity ◦ Hylarana erythraea lives for about four years and Fejervaria cancrivora about three years Frog Calls ◦ Mating calls ◦ Warning signals ◦ Distress calls ◦ Release calls Vocalization nearly the exclusive domain of frogs frog calls typically contain 3 or fewer notes; lasts less than 2 seconds and may be repeated rapidly in sets 40 – 4000 Hz; good broadcast spectrum, avoiding acoustic interferences from other sounds loudness of calls: not size related Frog Courtship dominated by frog auditory signals (vocalization) Male frog calls: allows female to select and locate males Other signals continue the courtship once in the vicinity of the male E.g. Bufo males: stops calling and grasps any female that comes near them Hyla males: amplex females only after the females have touched them Polypedates leucomystax: requires female to posture in front of the male Parental care of young ◦ Observed in Limnonectes leytensis ◦ Adult frogs were observed to sit on eggs Aestivation ◦ Occidozyga laevis, Fejervaria cancrivora probably aestivate during dry season in regions with definite dry and wet season ◦ Burrow in muds or wet soil Feeding Habits ◦ Larvae ◦ Filter feeders (Megophrys monticola, Kaloula conjuncta) ◦ Algae-scrapers ◦ Adult Amphibians are carnivorous ◦ Use their sense of sight, some use sense of smell Escape and Defense ◦ Some exude water from their cloacas ◦ A frogs when held by human hands will go limp and when relaxed will suddenly kick itself out of the hand ◦ Inflate to discourage predators ◦ Secrete poison ◦ Defend territory thru fighting Escape and Defense