SEAVR 2019: 074‐075
ISSN: 2424‐8525
Date of publication: 06 November 2019
Hosted online by ecologyasia.com

Interspecific amplexus between Ingerophrynus philippinicus
and Megophrys ligayae on Palawan Island, Philippines
Antonio N. LORENZO II & Nikki Dyanne C. REALUBIT
antoniolorenzo6792@gmail.com (Lorenzo)

Observers: Antonio N. Lorenzo II, Jowb Czechariah Borja, Jessa Belle Garibay, Nikki Dyanne C. Realubit.
Photograph by: Antonio N. Lorenzo II.
Subjects identified by: Antonio N. Lorenzo II, Nikki Dyanne C. Realubit.
Location: Cleopatra’s Needle Critical Habitat (CNCH), Barangay Binduyan, Puerto Princesa City, Palawan Island,Philippines.
Elevation: 150 metres ASL.
Habitat: Rocky riverine edge in a lowland, secondary forest.
Date and time: 02 February 2019, 22:00 hrs.
Identity of subjects:(i) Philippine Toad, Ingerophrynus philippinicus (Amphibia: Anura: Bufonidae)(ii) Palawan Horned Frog, Megophrys ligayae (Amphibia: Anura: Megophryidae)
Description of record: An interspecific amplexus between a male Philippine toad (SVL=68 mm) and a female
Palawan Horned frog (SVL=73 mm) was documented (Fig. 1). The unusual pair was observed on a river bankduring a herpetological survey. They were not immersed in water and the female frog did not produce any eggs
during the time of observation.

Fig. 1.

© Antonio Lorenzo II74

Remarks:
The two anuran species observed are both endemic to the Palawan Island Group. The male Philippine ToadIngerophrynus philippinicus was identified based on the prominence of two cranial crests resembling a crown(Inger, 1954). The female Palawan Horned Frog Megophrys ligayae was identified based on the presence of its
orbital appendages resembling horns (Inger, 1954), hence its common name. The former species looks similar toanother bufonid Rhinella marina which was introduced in the country during the early 20th century as a
biological control agent. The latter species, Megophrys ligayae, which is restricted in terms of its distribution, ispresent only in the Palawan Island group and closely resembles its congeneric, the Mindanao Island endemic M.
stejnegeri.
During breeding season, male and female anurans communicate through visual, chemical and acoustic signals andone of the ways to successfully breed is through amplexus (Wells, 2007; Belanger and Corkum, 2009). Anuran
amplexus is characterized by the male frog grasping on the female forcing it to release eggs and external
fertilization immediately follows (Vivek et al., 2014). However, interspecific amplexus is a rare occurrence among
anurans with a relatively low number of published observations (Groffen et al., 2019). This kind of interaction
between two different anuran species happens due to the inability of the male to detect and recognize
conspecific females especially during times of active breeding among different anuran species in the same area orhabitat (Londero et al., 2018). This kind of interaction also happens due to the absence of niche segregation
among anuran species with overlapping breeding periods and habitats combined with increased pressure tobreed (Beranek, 2017). To our knowledge, this is the first record of interspecific amplexus between the endemic
Philippine Toad and the Palawan Horned Frog.
References:
Inger, R. (1954). The systematics and zoogeography of Philippine Amphibia. Fieldiana 33: 181‐531.
Belanger, R. & Corkum, L. (2009). Review of aquatic sex pheromones and chemical communications in anurans.
Journal of Herpetology 43 (2): 184‐191.
Beranek, C. (2017). Natural history notes. Litoria dentata and Litoria peronii. Interspecific amplexus.
Herpetological Review 48 (2): 411.
Groffen, J., Yang, Y., Borzée, A. & Jang, Y. (2019). Interspecific amplexus between Glandirana teintaiensis (Chang,1933) and Odoranna schmackeri (Boettger, 1892) at the Fuchun River, eastern China. Herpetology Notes 12: 41‐42.
Londero, J., Feltrin, R., da Rocha, M., Schuch, A. & dos Santos, M. (2018). Interspecific amplexus between twotreefrogs of the genus Boana Gray, 1825 (Anura: Hylidae) in captivity male‐female and male‐male pairings.
Herpetology Notes 11:413‐415.
Vivek, S., Dinesh, M., Kumar, K., Divaker, Y. & Sharma, K. (2014). Interspecies mating interactions between
Duttaphrynus stomaticus (Marbled Toad) and Sphaerotheca breviceps (Indian burrowing frog) at the Central
Aravalli foothills, Rajasthan, India. Herpetology Notes 7: 139‐140.
Wells, K. (2007). The ecology and behavior of amphibians. Chicago, Illinois, USA, University of Chicago Press.

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