Palawan Research Articles

The ecology of Altrichthys azurelineatus and A. curatus, two damselfishes that lack a pelagic larval phase

Out of more than 380 species of damselfish, only three lack a pelagic larval phase, Acanthochromis polyacanthus, that ranges from the Philippines to the Great Barrier Reef, and two species in the genus Altrichthys, A. azurelineatus and A. curatus, that are restricted to the Calamian Archipelago (Palawan province) in the Philippines. Therefore in a very restricted geographic area, northern Palawan, Philippines, all three species co-occur. The goal of this study was to fill a knowledge gap about the ecology of Altrichthys, where very little is currently known. Using census and behavioral approaches at 14 sites on six islands, we were able to identify adult densities, nest densities, nesting habitat preference, and brood behavior and abundance. We found that densities were very high (more than 17 individuals/100 m2 for one species) and A. azurelineatus may be displacing A. curatus at deeper depths where habitat seems of higher quality. Only one out of 14 surveyed sites contained only one species, Altrichthys curatus. Different habitat use and feeding behavior suggest that niche partitioning may play an important role in the life history of these sympatric species.

A New Supple Skink, GenusLygosoma(Reptilia: Squamata: Scincidae), from the Western Philippines

Abstract: The Palawan Pleistocene Aggregate Island Complex, a western Philippines island group, possesses a complex geologic history and numerous endemic vertebrates. On the basis of multiple unique morphological features, bolstered by genetic data supporting divergent lineages, we describe the first Philippine endemic species of Lygosoma from Palawan and Cuyo islands. This new semifossorial species is phenotypically similar to Lygosoma quadrupes, a widespread Southeast Asian scincid lizard. We recognize the Palawan lineage as a new species, the second member of the L. quadrupes species complex, and comment on its ecology and conservation status. This new species increases species-level diversity in the genus to 31, including 19 species distributed across Southeast Asia.

Diversity and structural complexity of mangrove forest along Puerto Princesa Bay, Palawan Island, Philippines

Abstract The paper describes the diversity and structural complexity of mangrove forest along Puerto Princesa Bay, Palawan Island, Philippines. Occurrence of 28 mangrove species and 11 floral associates were found, which identifies the entire bay as one of the most diverse mangrove forests in the country. Of the six coastal barangays surveyed, San Pedro had the highest diversity index, H′ = 0.912 while Sta Monica had the lowest, H′ = 0.349. Mangrove stands are structurally simple with two types of vegetation, fringe and riverine that further constitute five distinct mangrove zones named according to dominating species, Rhizophora - Sonneratia ; Rhizophora-Sonneratia-Lumnitzera ; Rhizophora-Lumnitzera-Xylocarpus ; Rhizophora-Xylocarpus ; and Rhizophora-Avicennia . Commonality among these zones is obvious as revealed in Bray-Curtis cluster analysis. Structural features differed across zones. Trees of larger dbh, 104.5 cm and higher species richness, a total of 15 species, were found in zone 1 while those that comprised the highest basal area, 438 m −2 ha −1 and density, 8100 ha −1 from zones 2 and 4, respectively. Zones 1 and 4 are fringing mangrove forests. Degrees of perturbations greatly depend on human access to mangrove areas. Garbage dumping, occasional cutting of trees, soil erosion, and encroachment of human settlers were identified as potential threats to mangrove forest along the bay.

A new narrow-leaved species of Capparis (Capparaceae) from central Palawan, Philippines

A new species of Capparis, C. tagbanuorum, is described and illustrated from Palawan Island in the Philippines. It is known from a single locality in Mount Victoria, in forest habitats at medium elevation. The new species is characterized by a peculiar leaf morphology, with blade up to 9 times as long as wide, by the racemose inflorescence and by the size of the petals and the number and length of the stamens. The diagnostic characters are discussed and a key is given for the species of Capparis known from the Philippines.

Robinson, A.S., Gironella, E.P. & Cervancia, J.M. (2016) New orchid species of Sigmatodactylus (Orchidoideae; Diurideae) and a new record of Cryptostylis carinata from central Palawan, Philippines. Phytotaxa 252 (2): 99–113.

Two new species of Stigmatodactylus from Palawan Island in the Philippines are described and illustrated. The taxa, which represent the first records for the genus Stigmatodactylus in the Philippines, are restricted to the ultramafic peaks of central Palawan. Cryptostylis carinata, originally described from New Guinea, is also documented, representing a first record for this species in Palawan.

New orchid species of Stigmatodactylus (Orchidoideae; Diurideae) and a new record of Cryptostylis carinata from central Palawan, Philippines

Two new species of Stigmatodactylus from Palawan Island in the Philippines are described and illustrated. The taxa, which represent the first records for the genus Stigmatodactylus in the Philippines, are restricted to the ultramafic peaks of central Palawan. Cryptostylis carinata, originally described from New Guinea, is also documented, representing a first record for this species in Palawan.

A Revision of the Selenocosmiine Tarantula GenusPhlogiellusPocock 1897 (Araneae: Theraphosidae), with Description of 4 New Species

The tarantula genusPhlogiellus(Pocock 1897) is revised. The genus is diagnosed against all other selenocosmiine genera for the first time along with a new generic description. The tribe Yamiini (Kishida 1920) is diagnosed against all other selenocosmiine tribes. AllPhlogiellusspecies are diagnosed from all congeners; all species are mapped. Complete dichotomous keys for both sexes of all species are included. Where appropriate, intraspecific variation is discussed. Four new species are described:P. bogadekisp. nov. from Hong Kong,P. johnreylazoisp. nov. from Palawan Island, Philippines,P. moniqueverdezaesp. nov. from Ranong, Thailand, andP. pelidnussp. nov. from Sabah, Borneo. The type speciesP. atriceps(Pocock 1897) holotype male is redescribed and the maleP. baeri(Simon 1877) is described in detail for the first time. The validity ofP. inermis(Ausserer 1871) is confirmed. Relationships between all known selenocosmiine genera andPhlogiellusfrom the Philippines are discussed and several character traits are newly diagnosed. The tribe Phlogiellini (West et al. 2012) is a junior synonym of Yamiini (Kishida 1920).Selenocosmia orophila(Thorell 1897) from Myanmar,Selenocosmia insulana(Hirst 1909) from Djampea (= Jampea) Island, andSelenocosmia obscura(Hirst 1909) from Sarawak, Borneo, are transferred toPhlogiellus, altering the specific names toPhlogiellus orophilus(Thorell 1897) comb. nov.,Phlogiellus insulanus(Hirst 1909) comb. nov., andPhlogiellus obscurus(Hirst 1909) comb. nov.Phlogiellus subarmatus(Thorell 1891) is transferred toChilobrachys(Karsch 1891), becomingChilobrachys subarmatus(Thorell 1891) comb. nov.Phlogiellus kwebaburdeos(Barrion-Dupo et al., 2014) is transferred toOrphnaecus(Simon 1892), becomingOrphnaecus kwebaburdeos(Barrion-Dupo et al., 2014) comb. nov.Phlogiellus ornatus(Thorell 1897) andPhlogiellus nebulosus(Rainbow 1899) are consideredspecies inquirenda.Phlogiellus baeri(Simon 1877) is no longer consideredincertae sedis;Phlogiellus bicolor(Strand 1911) andPhlogiellus insularis(Simon 1877) are consideredincertae sedis.

A forest of dreams: Ontological multiplicity and the fantasies of environmental government in the Philippines

How do invisible beings in the forested hinterlands complicate the work of bureaucrats in the capital? What do dreams and the beings who visit them have to do with state power? Despite a deepening commitment to posthumanism, political ecologists have rarely opened our accounts of more-than-human assemblages to what have conventionally been termed “supernatural” or “metaphysical” forms of agency. To counter this lingering ethnocentrism, I argue here for an ontologically broadened understanding of how environmental government is produced and contested in contexts of difference. My argument draws on ethnographic fieldwork on Palawan Island in the Philippines, where the expansion of conservation enclosures has coincided with the postauthoritarian recognition of Indigenous rights. Officials there have looked to a presumed Indigenous subsistence ethic as a natural fit for conservation enclosures. In practice, however, Palawan land- and resource-use decisions are based, in part, on social relations with an invisible realm of beings who make their will known through mediums or dreams. These relations involve contingencies that complicate and at times subvert the designs of bureaucratic conservation. As a result, attempts to graft these designs onto Palawan practices do as much to engender mutually transformative encounters between contrasting ontological practices as they do to create well-disciplined eco-subjects or establish state territoriality. To better understand the operation of environmental government – and to hold it accountable to promises of meaningful local participation – political ecology should, I argue, attend more carefully to the ontological multiplicity of forces that shape spatial practices and their regulation.

Gynochthodes leonardii: a novel species of Morindeae-Rubiaceae from Palawan, Philippines

Gynochthodes leonardii, a new taxon from vegetations on ultramafic substrates in the northern and central regions of Palawan province, Philippines is described and illustrated. It is superficially similar to G. bartlingii but is readily recognized by the induments on its vegetative and reproductive structures, sulcate and lenticeled branches, scarious and deciduous stipules, 3–9 capitula in an inflorescence, and shorter corolla tubes.

Mobility of early islanders in the Philippines during the Terminal Pleistocene/Early Holocene boundary: pXRF-analysis of obsidian artefacts

The Philippine archipelago spans over two distinct biogeographic zones, Sundaland and Wallacea. We report in this paper on finds from Ilin Island just off the coast of SW-Mindoro, and El Nido in Northern Palawan. While the island of Palawan is linked to Sundaland, Mindoro and Ilin Island belong to Wallacea, east of Huxley's Line. Ongoing archaeological investigations at Bubog 1 Rockshelter on Ilin Island and Ille Cave & Rockshelter in northern Palawan, delivered obsidian artefacts, found in Terminal Pleistocene and Early Holocene layers. PXRF analysis of the obsidian samples from Mindoro and Palawan shows that they were coming from the same, yet unknown source. They clearly indicate that the two distinct paleogeographical regions were linked to each other, suggesting human interaction and maritime networks as early as ca. 12ka BP. The results of this study contribute substantially to our understanding of the mobility of early islanders during the Terminal Pleistocene and the processes of human island adaptation and enhance our current knowledge of subsistence strategies across the region.

First record of association of copepods with highly venomous box jellyfish Chironex, with description of new species of Paramacrochiron (Cyclopoida: Macrochironidae).

Paramacrochiron chironecicola n. sp. (Copepoda: Cyclopoida: Macrochironidae) is described from the highly venomous box jellyfish Chironex sp. collected from Malampaya Sound, Palawan Island, The Philippines. This is the first record of copepods associated with cubozoan medusae, although other cnidarian groups such scyphozoans, hydrozoans, and anthozoans are common hosts for symbiotic copepods. The infection sites were on the subumbrella, pedalium, and rhopalium, but also rarely on the adradial furrow. The new species is distinguished from other congeners by a combination of the following features: (1) the fifth pedigerous somite dorsally covering the anterior part of the female genital double-somite; (2) the fine structures of the antenna (relative lengths of segments) and maxilliped (positions of terminal elements) of the female; (3) the relatively long outer spines on the exopodal segments of legs 1-4; (4) the relatively long and thick female leg 5 bearing a long protopodal seta which reaches to the distal margin of the exopod; (5) the relatively short caudal ramus in the female; and (6) the plump prosome and short urosome in the male. Since members of the genus typically parasitize scyphozoans, especially rhizostomes, the association of this parasitic copepod on cubozoans may reflect the relatively close phylogenetic relationship between cubozoans and scyphozoans.

Flora of Mt. Mantalingahan Range, Palawan Island, Philippines: Basis for Prioritizing Protected Areas

In Palawan Island, Philippines, Mt. Mantalingahan is given high conservation value because its varied habitats harbor different organisms including important wildlife, but little is known about its floristic composition. Using the Variable Transect Method for Rapid Assessment of Tropical Plant Communities, its peripheral forest flora in four surrounding municipalities was surveyed to describe the community structure and assess the priority areas for protection. The mountain’s peripheral forest is rich in diversified flora having at least 351 species in 214 genera and 92 families. Endemism is remarkably high having at least 50 species of which nine are only found in Palawan, higher than the six species found in Puerto Princesa City Underground River National Park. It contains numerous plant species that are rare with narrow habitat range, economically important, and 13 vulnerable, four endangered and five critically endangered. From the criteria in prioritizing areas for protection, Rizal municipality ranked first, followed by Bataraza, Sofrono Española, and Brooke’s Point municipalities. Results from rapid floral assessment demonstrate that Mt. Mantalingahan Range is one of the most important sites in Palawan Corridor for biodiversity conservation. The best and strictest measures should be applied to prevent any degradation of such a rich genetic resource. Keywords - Plant Ecology, flora, threatened species, ecological design, Palawan, Philippines

Violent enclosures, violated livelihoods: environmental and military territoriality in a Philippine frontier

The political geography of environmental governance can overlap and converge with uneven agrarian change in forest frontiers subject to violent enclosures. When the governance of conservation territories converges with and reinforces enclosures, spaces can be controlled with authority and violence that places livelihoods at greater risk in the context of uneven agrarian political economies – the outcomes of which reflect ‘violent enclosures’. This paper examines how indigenous resource users negotiate the discursive and material impact of environmental governance converging with militarized-insurgent spaces as overlapping enclosures in a protected area on Palawan Island, the Philippines. Drawing on local experiences, we examine how the livelihood vulnerability arising in the local political economy is exacerbated by access and use constraints from the overlapping enclosures of environmental and military governance in the buffer zone of Puerto Princesa Subterranean River National Park. We argue that the seemingly less governable forest frontiers of protected areas are often the poorest, highly politicized and contested spaces of political and ecological refuge. Here, scarce forest resources are managed closely, and recalcitrant groups seek refuge as military powers frame, conflate and manage local behaviour as criminal and dangerous, merging conservation and military interventions as coercive governance. We conclude that only by critically engaging how governance processes and enclosures converge to yield structural and discursive violence – and by making this apparent to policy makers – will indigenous peoples successfully negotiate the double bind of violent enclosures in frontiers.

Late Quaternary Sea-Level Changes and the Palaeohistory of Palawan Island, Philippines

ABSTRACTPalaeogeographic reconstructions of Palawan Island using Geographic Information Systems based on present-day bathymetry show extensive changes in land area with respect to sea-level fluctuations during the Late Quaternary. Our analysis shows that a lowering of at least 135 meters from present-day levels is needed in order to expose a narrow land connection between Palawan and Sundaland. This most likely last occurred during OIS 12 (ca. 440 Ka) and probably OIS 16 (ca. 630 Ka), facilitating overland colonization between the two islands. The reconstructions further illustrate the extent of land exposed, which was likely covered by open savannah vegetation during the LGP and inhabited by several large mammal species now extinct on the island. Sea-level rise at the end of the Pleistocene caused the inundation of shallow shelves of Palawan, and this, accompanied by a conversion to closed rainforest environments, was probably responsible for the disappearance of most of the large mammal fauna of Palawan. Coastline reconstructions demonstrate that the appearance of mid-Holocene shell middens in the Philippine archaeological record is due to the formation and proximity of mangrove forests during sea-level high-stand, rather than a consequence of changes in human subsistence strategies.

Divergence history of the Rufous-tailed Tailorbird (Orthotomus sericeus) of Sundaland: Implications for the biogeography of Palawan and the taxonomy of island species in general

ABSTRACT The Rufous-tailed Tailorbird (Orthotomus sericeus)—a Sunda endemic—is divided into 3 morphologically based subspecies: one in western Sundaland (Malay Peninsula, Sumatra, and associated islands), one from the Natuna Islands in the South China Sea, and one on Borneo, Palawan, and smaller islands of the Sunda continental shelf east of Borneo. Previous study, however, suggested that these subspecies do not conform to molecular genetic subdivisions of the species. We reexamined the morphology and performed molecular phylogeographic and multi-locus coalescent analysis of two subspecies of Rufous-tailed Tailorbird comprising populations on the Malay Peninsula, Sumatra, Borneo, and Palawan. We found (1) little morphological difference among the two subspecies, (2) no substantial genetic differences between the Borneo and western Sunda populations, but (3) marked genetic divergence between the Palawan and other populations. We conclude that the Bornean and western Sunda populations interbred extensively ...

A New Eclogavena (Gastropoda: Cypraeidae) from the Northern Sulu Sea, Philippines

A new cypraeid cowrie shell of the genus Eclogavena Iredale, 1930 is described from the northern Sulu Sea, southern Philippine Islands. The new taxon, Eclogavena dayritiana mondejarorum Petuch and Myers, new subspecies, is described as a subspecies of the widespread Sulu Sea E. dayritiana (Cate, 1963) and differs in being a more inflated and lighter-colored, pale blue and white shell. The new subspecies is also compared to the closely-related E. dani (Beals, 2002) from deep water off Palawan Island, Sulu Sea, but differs in being a less pyriform, less inflated, and much lighter colored shell. The three Sulu Sea Eclogavena species differ greatly in their ecological and bathymetric preferences: E. dayritiana lives under coral rubble in intertidal depths, and is often exposed at low tide; E. dani prefers coral rubble areas in 25-150 m depths; and E. dayritiana mondejarorum lives only inside giant sponges, growing on steep reef walls, in 30 m depth. The three closely-related taxa appear to represent a localized species radiation of Eclogavena cowries that is confined to the Sulu Sea.

The Forest Types in Aborlan Guba System, Palawan Island, Philippines

A floral survey was conducted in Aborlan Guba System, Aborlan, Palawanfollowing the quadrat technique of vegetation analysis by Mueller-Dombois &Ellenberg (1974) and Pacardo et al. (2000) to determine the forest zonationtherein and the environmental variables that influenced the vegetation pattern.Sixty-six quadrats, each for trees (10m x 10m) and saplings (2m x 2m) andseedlings and herbaceous vegetations (1m x 1m), were established throughout thestudy area. Four vegetation associations were distinguished from cluster analysis.Results of multivariate regression analysis reveal that elevation, air temperature,moisture content, water holding capacity, pH and potassium level of the soil, andhuman disturbance significantly influenced the spatial distribution of tree species.Human impact was inversely proportional to species richness (r2= 0.968). Sincethe area is encroached by the locals, the whole area must be categorized as a CoreZone for its immediate protection. Declaring it as a Protected Area under theNIPAS law ensures the long-term protection of the system.Keywords: Ecology, Forest, vegetation association, environmental factors, Palawan,Philippines

A new mangrove-inhabiting porcelain crab of the genus <I>Enosteoides</I> (Crustacea: Decapoda: Anomura) from Puerto Princesa Bay, Palawan, the Philippines

A mangrove-inhabiting porcelain crab, Enosteoides philippinensis sp. nov., is described based on material collected from Palawan Island, the Philippines. It is the fifth species of the genus and different from its congeners in having an extremely setose body, one to five spines on the proximal half of the outer margin of the chela, two lobes on the anterior margin of the basal article of the antennular peduncle, and two to four strong spines on the mesobranchial regions.

Aquatic Coleoptera of the Lake Manguao Catchment, Palawan, the Philippines

Results of an inventory of the aquatic and paraaquatic beetle fauna (Insecta: Coleoptera) of small streams in a lake catchment of northern Palawan are presented. Thirty-two sample sites and the sampling methods used are described herein. A total of 56 species taxa were recorded, with the majority of the collected material determined to species level. References and information on ecology, distribution and collection sites are given for each identified taxon. Some taxa are recorded for the first time in the Philippines, and endemic and undescribed taxa are discussed. Additional environmental data of the sampled aquatic and the surrounding terrestrial habitats are provided and discussed in comparison with data of previous surveys in the area.

Associations of fish juveniles with rhizostome jellyfishes in the Philippines, with taxonomic remarks on a commercially harvested species in Carigara Bay, Leyte Island

A wide variety of fish and invertebrates are associated with marine jellyfishes, and their interactions are diverse. We preliminarily investigated symbionts on two species of rhizostome jellyfishes collected from Leyte and Palawan Islands, the Philippines, in August 2013. The collected jellyfishes were Lobonemoides robustus Stiasny on both islands and Acromitus maculosus Light on Palawan Island. Lobonemoides robustus is commercially harvested on both islands, and seems to have been previously misidentified as Lobonema smithi Mayer. The associated fish ju- veniles on these hosts were identified as Alepes djedaba (Forsskal) and Carangoides equula (Temminck & Schlegel). Alepes djedaba is closely associated with many species of scyphozoan jellyfish broadly in the southeastern Asian wa- ters. The associations of carangids with jellyfish are also reviewed.