SEAVR 2020: 001‐003
ISSN: 2424‐8525
Date of publication: 25 January 2020
Hosted online by ecologyasia.com

In situ parental observation of male Limnonectes leytensis
eggs in Sambonotan Watershed, Dinagat Islands, Philippines
Erl Pfian T. MAGLANGIT, Olive A. AMPARADO & Rod Vincent L. BORROMEO
erlpfianmaglangit@gmail.com, olive.anies@g.msuiit.edu.ph, vinceborromeo6@gmail.com

Observers: Erl Pfian T. Maglangit, Olive A. Amparado, Rod Vincent L. Borromeo, Ruben F. Amparado Jr., Rolly B.
Caballero.
Photographs by: Erl Pfian T. Maglangit.
Subject identified by: Arvin C. Diesmos, Rafe M. Brown.
Location: Sambonotan Watershed, Barangay Mabini, Municipality of Tubajon, Dinagat Islands, northeastern
Mindanao, Philippines (N10°19.29’ E125°36.45’; WGS 84).
Elevation: 69 metres ASL.
Habitat: Mature, secondary growth, lowland forest.
Date and time: 12 November 2018, 14:30 hrs.
Identity of subjects: Leyte Swamp Frog (Leyte Wart Frog), Limnonectes leytensis (Amphibia: Anura; Dicroglossidae)
Description of record: During a herpetofaunal survey in Sambonotan Watershed, we observed a clutch of eggs ofLeyte Swamp Frog Limnonectes leytensis. (Fig. 1). A total of 98 eggs in a single clutch of L. leytensis were counted,
situated along an obliquely‐angled wood vine, which were encapsulated in a 4 mm thick, dense, transparent jelly‐
like envelope approximately 7.0‐7.5mm across and in a stage‐22 of an egg‐adult formation of frogs (Gosner,1960). Tail buds were clearly visible with progressive neural formation and development of other differentiatedbody parts including the head, which is prominent in a pale‐yellow colouration and with different patterns ofpigmentation.

Fig. 1. L. leytensis eggs in situ

© Erl Pfian T. Maglangit

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An adult male L. leytensis (snout‐vent‐length: 29.4 mm) was observed clinging to a wood vine 13 cm beneath theclutch of eggs, and 56cm above a clear pond of water (20 cm in depth, pH = 6.0), and 2 metres from a nature trail(Fig. 2). The frog appeared to be safeguarding the eggs against natural predators. The habitat in the area (Fig. 3) iscomposed of re‐growing dipterocarp forest with dense understorey vegetation, and a forest floor dominated byleaf litter in a slightly mineralized, reddish, clay‐loam soil (pH = 5.1). The forest was relatively humid (RH = 98%)
with an air temperature range of 26.0‐27.6°C, which potentially maintains the moisture of the environment andprevents dehydration of the eggs.

Fig. 2. Adult male L. leytensis perched on diagonal wood vine

© Erl Pfian T. Maglangit

Fig. 3. L. leytensis eggs hanging on wood vine in mature secondary forest.

© Erl Pfian T. Maglangit2

Remarks:
The Leyte Swamp Frog Limnonectes leytensis is a Philippine endemic fanged frog, formerly known as Ranamicrodisca leytensis (Inger, 1954). It is a medium‐sized frog with (i) a fang‐like odontoid process on the lower jaw,(ii) smooth dorsal skin, (iii) tympanum hidden on a dorsal edge, (iv) presence of irregular dorsal fold ridges and (v)a prominent supratympanic fold (Siler et al. 2009; McLeod, 2010).
It is known to occur on the islands of Leyte, Samar, Bohol, Camiguin Sur, Cebu, Negros, Mindanao, Romblon
Island Group, Basilan, Sulu Archipelago and Dinagat (Siler et al. 2009; Diesmos et. al 2015; Sanguila et al. 2016)
and is mostly found in swamps, streams and riparian areas in primary and secondary forest habitat.
Fanged frogs have a unique parental behavior wherein most of its male individuals invest parental care, rather
than its females (Vallejos et al. 2018). This includes guarding of terrestrial eggs, transporting of tadpoles on theback and flanks and carrying developing tadpoles in the vocal sacs (Iskandar et al. 2014). Male parental care ofPhilippine fanged frogs is quite uncommon or undocumented. Nevertheless, it is widespread and potentially plays
an important role in the success and survival of the species throughout the clade in Southeast Asia.
To the best of our knowledge, there are no published accounts on the Philippine Limnonectes group that
demonstrates male parental behavior and displays exceptional nesting clutch placement. Our field observations
provide new information on male parental care, clutch size and nesting site preference of L. leytensis in theDinagat Islands.
Note: No voucher specimens were collected. Images shown here were deposited at the digital archive of the Lee
Kong Chian Natural History Museum, National University of Singapore (NUS) and are permanently cataloged(Code: ZRC, IMG 1.183‐1.184).
Acknowledgements: We thank the Philippine Department of Environmental and Natural Resources through
DENR CARAGA Region VIII for providing research permits (Philippine Wildlife Gratuitous Permit No: R13‐2018‐65).
Funding support was provided by the Department of Science and Technology‐Science Education Institute throughAccelerated Science and Technology Human Resource Development Program (DOST‐ASTHRDP). We are also
grateful to the Local Government Unit of Municipality of Tubajon for logistics and to Mr. Kelvin Lim Kok Peng ofthe Lee Kong Chian Natural History Museum (LCNHM) of the National University of Singapore for technicalsupport in cataloguing photographic vouchers.
References:Diesmos, A. C., Watters, J. L., Huron, N.A., Davis, D.R., Alcala, A.C., Crombie, R.I., Afuang, L.E., Das, G. G., Sison, R.
V., Sanguila, M. B., Penrod, M. L., Labonte, M. J., Davey, C. S., Leone, A. E., Diesmos, M. L., Sy, E. Y., Welton, L. J.,Brown, R. M. and Siler C. D. (2015). Amphibians of the Philippines, Part I: checklist of the species. Proceedings ofthe California Academy of Sciences. 62: 451–531.
Gosner, K. (1960). A simplified table for staging anuran embryos and larvae with notes on identification.
Herpetologica. 16 (3), pp. 183‐190.
Iskandar, D. T., Evans, B. J., and McGuire, J. A. (2014). A novel reproductive mode in frogs: A new species of fanged
frog with internal fertilization and birth of tadpoles. PLoS ONE. 9(12). Retrieved from: doi:10.1371/journal.pone.
0115884.
Sanguila, M. B., Cobb, K. A., Siler, C. D., Diesmos, A. C., Alcala A. C., and Brown, R. M. (2016). The amphibians andreptiles of Mindanao Island, southern Philippines, II: the herpetofauna of northeast Mindanao and adjacentislands. ZooKeys. 624: 1–132 (2016). Retrieved from: doi: 10.3897/zookeys.624.9814 http://zookeys.pensoft.net.
Siler, C. D., McVay, J. D., Diesmos A. C., and Brown R. M. (2009). A New Species of Fanged Frogs, Genus
Limnonectes (Amphibia: Anura: Dicroglossidae) from Southeast Mindanao Islands. Herpetologica. 65 (1), pp. 105‐114.
Vallejos, J. G., Grafe, T. U. and Wells, K. D. (2018). Prolonged parental behaviour by males of Limnonectes
palavanensis (Boulenger 1894), a frog with possible sex‐role reversal. Journal of Natural History. 52:37‐38, pp.
2473‐2485.

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