Feeding biology and symbiotic relationships of the corallimorpharian Paracorynactis hoplites (Anthozoa: Hexacorallia)

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Abstract
Polyps of the corallimorpharian Paracorynactis hoplites were studied in coral reefs of the Davao Gulf, the Philippines, between October 2007 and January 2009. Polyps of Paracorynactis hoplites preyed mainly on echinoderms. Predation on seven species of echinoderms was observed in the fi eld (four asteroids, two echinoids and one holothurian); an additional ten species were accepted during feeding trials (four asteroids, four echinoids and two holothurians). The echinoids Diadema setosum, Diadema savignyi and Echinotrix calamaris, and the ophiuriod Ophiomastix sp. were not adversely affected by the polyps. The opisthobranch Phyllidiella pustulosa (Mollusca) was accepted during feeding trials, whereas the gastropod Cypraea tigris was not adversely affected. In a feeding experiment, polyps of Paracorynactis hoplites (maximum diameter 170 mm) completely ingested crown-of-thorns sea stars (Acanthaster planci) of up to 340 mm diameter. The polyps had a mean daily biomass uptake of 24.5 g d-1 when having a single-species asteroid diet. Fishes of several species of families Apogonidae, Gobiidae, Labridae, Pomacentridae, and Pseudochromidae as well as the shrimps (Periclimenes holthuisi, Periclimenes lacerate, Stenopus hispidus and Thor amboinensis) lived near or among the tentacles of the polyps.

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245
THE RAFFLES BULLETIN OF ZOOLOGY 2011
FEEDING BIOLOGY AND SYMBIOTIC RELATIONSHIPS OF THE
CORALLIMORPHARIAN PARACORYNACTIS HOPLITES
(ANTHOZOA: HEXACORALLIA)
Arthur R. Bos
German Development Service – D.E.D., 11
th
Floor P.D.C.P. Bank Center Building, V.A. Rufi no corner L.P. Leviste Streets,
Salcedo Village, 1227 Makati, The Philippines
Department of Marine Zoology, Netherlands Center for Biodiversity Naturalis, P.O. Box 9517, 2300 RA Leiden, The Netherlands
Biology Department, American University in Cairo, P.O. Box 74, New Cairo 11835, Egypt
E-mail: arthurrbos@yahoo.com (Corresponding author)
Benjamin Mueller
Royal Netherlands Institute for Sea Research, P.O. Box, Texel, The Netherlands
Girley S. Gumanao
Research Offi ce, Davao del Norte State College, New Visayas, 8105 Panabo, The Philippines
ABSTRACT. Polyps of the corallimorpharian Paracorynactis hoplites were studied in coral reefs of the
Davao Gulf, the Philippines, between October 2007 and January 2009. Polyps of Paracorynactis hoplites
preyed mainly on echinoderms. Predation on seven species of echinoderms was observed in the fi eld (four
asteroids, two echinoids and one holothurian); an additional ten species were accepted during feeding trials
(four asteroids, four echinoids and two holothurians). The echinoids Diadema setosum, Diadema savignyi
and Echinotrix calamaris, and the ophiuriod Ophiomastix sp. were not adversely affected by the polyps. The
opisthobranch Phyllidiella pustulosa (Mollusca) was accepted during feeding trials, whereas the gastropod
Cypraea tigris was not adversely affected. In a feeding experiment, polyps of Paracorynactis hoplites
(maximum diameter 170 mm) completely ingested crown-of-thorns sea stars (Acanthaster planci) of up to
340 mm diameter. The polyps had a mean daily biomass uptake of 24.5 g d
-1
when having a single-species
asteroid diet. Fishes of several species of families Apogonidae, Gobiidae, Labridae, Pomacentridae, and
Pseudochromidae as well as the shrimps (Periclimenes holthuisi, Periclimenes lacerate, Stenopus hispidus
and Thor amboinensis) lived near or among the tentacles of the polyps.
KEY WORDS. Acanthaster planci, Asteroidea, commensalism, crown-of-thorns, Echinodermata, Echinoidea,
Pseudocorynactis, Teleostei.
THE RAFFLES BULLETIN OF ZOOLOGY 2011 59(2): 245–250
Date of Publication: 31 Aug.2011
© National University of Singapore
INTRODUCTION
Polyps of Paracorynactis hoplites (Corallimorpharia) were
rst recorded from the Torres Strait near Papua New Guinea
(Haddon & Shackleton, 1893) and had long been considered
to belong to the genus of Pseudocorynactis. Recently, the
polyps were taxonomically described and added to the
new genus Paracorynactis (Ocaña et al., 2010). Polyps of
Paracorynactis hoplites occur in some reefs of Indonesia (den
Hartog, 1997), Malaysia (Gosliner et al., 1996), the Marshall
Islands (Colin & Arneson, 1995), and the Philippines (Bos
et al., 2008a). Little is known about the biology and ecology
of this species.
Polyps of Paracorynactis hoplites are found at depths
between 1–28 m, but the majority lives in water of less than
10 m (Ocaña et al., 2010). Independent of depth, the animals
prefer to settle under coral ledges and in reef crevices (Bos
et al., 2008a). The diameter of a single polyp can be as small
as 2 mm in preserved specimens (Ocaña et al., 2010) and
reach an impressive 210 mm in live specimens (Bos et al.,
2008a). Den Hartog et al. (1993) inferred from the size of
the nematocysts in the acrospheres that the polyps of this
corallimorpharian may be highly effi cient predators. Bos et
al. (2008a) reported that polyps prey on the relatively large
asteroids Acanthaster planci and Protoreaster nodosus,
and described how a polyp can quickly extend itself when
attacking an asteroid and how the prey is pulled toward the
polyp’s mouth and fully ingested. In this paper, we provide
new information about the feeding biology, behaviour, and
symbiotic relationships of Paracorynactis hoplites.
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Bos et al.: Feeding biology of Paracorynactis hoplites
MATERIAL AND METHODS
Polyps of Paracorynactis hoplites were studied on Samal and
Talikud islands, Davao Gulf, the Philippines, during 29 dives
to a depth of 37 m between Oct.2007 and Jan.2009. Location
and depth of each individual polyp (N = 72) were recorded,
and the diameter of each was measured to nearest cm. Prey
items and symbionts were recorded and photographed. Froese
& Pauly (2008) and Lieske & Myers (2002) were used to
identify symbiotic reef fi shes. Clark & Rowe (1971) and
Colin & Arneson (1995) were used to identify echinoderms,
mollusks, and shrimps. For the identifi cation of symbiotic
shrimps, we additionally used Bruce (1992).
Feeding behaviour was studied in 11 polyps observed by
skin-diving on a patch reef extending to 4 m depth at the
western coast of Samal Island (7º0.80'N, 125º43.24'E). The
column diameter and length of all polyps were measured
before and while they were feeding. To study food preference,
polyps were offered common asteroids and echinoids. To
study the effect of prey size, from Nov.2007 to Mar.2008,
specimens of the asteroid Acanthaster planci were offered
to the corallimorpharians. The asteroids were collected at a
nearby reef because none were found in the patch reef where
Paracorynactis hoplites was present. Animals of a variety of
sizes were offered: the diameter of each was measured before
releasing it near a polyp. If it moved away from the polyp,
Table 1. Species of Echinodermata and Mollusca naturally preyed upon (Prey) and fed to polyps (Fed) of the corallimorpharian Paracorynactis
hoplites in the Davao Gulf between Oct.2007 and Jan.2009.
Phylum/Class Species Author Prey Fed
Echinodermata
Asteroidea Acanthaster planci (Linnaeus, 1758) × ×
Archaster typicus (Müller & Troschel, 1840) ×
Choriaster granulatus Lütken, 1869 ×
Culcita novaeguineae Müller & Troschel, 1842 ×
Linckia laevigata (Linnaeus, 1758) × ×
Nardoa tuberculata Gray, 1840 ×
Pentaster obtusatus (Bory de St. Vincent, 1827) ×
Protoreaster nodosus (Linnaeus, 1758) × ×
Echinoidea Diadema setosum (Leske, 1778) not affected
Diadema savignyi Michelin, 1845 not affected
Echinometra mathaei (Blainville, 1825) × ×
Echinotrix calamaris (Pallas, 1774) not affected
Metalia spatagus (Linnaeus, 1758) ×
Brissus latecarinatus (Leske, 1778) ×
Phyllacanthus imperialis (Lamarck, 1816) ×
Salmacis belli Döderlein, 1902 ×
Toxopneustes pileolus (Lamarck, 1816) ×
Holothuroidea Holothuria hilla Lesson, 1830 ×
Holothuria leucospilota (Brandt, 1935) ×
Synapta maculata (Chamisso & Eysenhardt, 1821) ×
Ophiuroidea Ophiomastix sp. not affected
Mollusca
Gastropoda Cypraea tigris Linnaeus, 1758 not affected
Opisthobranchia Phyllidiella pustulosa (Cuvier, 1804) ×
the asteroid was picked up and put back near until it moved
toward the polyp. If a sea star was able to free itself from a
polyp’s tentacles, it was offered to a larger polyp.
To estimate biomass uptake, three polyps were enclosed
in individual cages of chicken wire (mesh size 10 × 10
mm
2
) with a surface area of about 0.2 m
2
. Each polyp was
fed asteroids of a single species diet (Acanthaster planci,
Linckia laevigata, or Protoreaster nodosus) during 7 wk and
had access to no other food. One free-roaming asteroid was
available in each cage allowing polyps to feed at any time.
Before being offered to a polyp, each asteroid was briefl y
removed from the water, blotted, measured, and weighed (1
g accuracy). The diameter of A. planci and the length of all
ve rays of L. laevigata and P. nodosus were measured. For
comparison, mean ray length (radius R) was multiplied by
two to calculate the diameter for the latter two asteroids.
RESULTS
Prey species. Polyps of Paracorynactis hoplites were
observed to prey largely on members of Echinodermata: four
species of Asteroidea and one species of Holothuroidea (Table
1). They were inferred to prey on two species of Echinoidea
from tests and spines found under or beside the polyps (Fig.
1). A feeding trial with the echinoid Echinometra mathaei
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THE RAFFLES BULLETIN OF ZOOLOGY 2011
confi rmed it to be an appropriate prey. In further feeding
trials, polyps of P. hoplites ingested other echinoderms
common in the vicinity, which increased the prey inventory
of members of the Echinodermata to a total of 17 species
(Table 1). However, three echinoids, Diadema setosum,
Diadema savignyi, and Echinotrix calamaris were not preyed
upon. Spines of these urchins could touch the tentacles of a
polyp without adverse effects (Fig. 2). Similarly, the arms
of a brittle star from the genus Ophiomastix could touch
the tentacles unaffected. One species of Opisthobranchia,
Phyllidiella pustulosa, was accepted as prey when offered
to the polyps, whereas the gastropod Cypraea tigris was not
affected (Table 1).
Polyps of Paracorynactis hoplites naturally prey on the
crown-of-thorns sea star, Acanthaster planci (Table 1). A
polyp can ingest a sea star larger in diameter than itself: the
larger the polyp, the larger the sea star it ingested (Fig. 3).
The largest sea star we observed to be ingested was 340 mm
in diameter (Fig. 3). Maximum diameters of Linckia laevigata
and Protoreaster nodosus ingested were 244 and 172 mm,
respectively. In the feeding experiments, the daily biomass
uptake was 29.5, 19.0, and 25.0 g d
-1
for the prey species
Fig. 1. Extended polyp of Paracorynactis hoplites pulling a partly
whitened asteroid (Linckia laevigata) toward its mouth. Note test of
echinoid Echinometra mathaei beside base of polyp (A. R. Bos).
Fig. 2. Echinoid Diadema savignyi not adversely affected by polyp
of Paracorynactis hoplites (A. R. Bos).
Fig. 3. Diameter of fully digested crown-of-thorns sea stars
(Acanthaster planci) as a function of polyp diameter of
Paracorynactis hoplites.
Acanthaster planci, Linckia laevigata, and Protoreaster
nodosus, respectively. The mean daily biomass uptake of a
polyp was 24.5 g d
-1
.
Prey capture. Polyps actively moved their tentacles to detect
potential prey. When acrospheres touched the surface of prey
items, they immediately stuck to the prey and remained fi rmly
attached. Subsequently the polyps expanded to bring as-yet
unattached acrospheres closer to the prey items. Some polyps
extended toward prey even before contact was made. After
extension and attachment of most acrospheres to prey items,
polyps slowly retracted, pulling the prey toward themselves.
Simultaneously, the polyp mouth opened and enveloped
the nearest parts of the prey item. Acrospheres continued
to attach, further entangling the prey. However, some prey
items escaped the pull of the tentacles, especially if they were
large or relatively fast moving, or if few acrospheres had
adhered to them. In cases where the prey had been moving
across a sandy bottom near the polyp, this appeared to be
an advantage to the polyp, because prey had relatively poor
traction on sandy substrate. About 50% of the polyps had
settled near sandy substrate.
Small and fl exible prey items were completely enveloped by
the mouth, then swallowed, which generally stretched the
polyp. After feeding, the polyp’s tentacles hung downward,
and when a potential prey item was touched to the tentacles,
the acrospheres had little adhesiveness. Asteroids that escaped
the pull of the tentacles after short contact with the polyps
were partly whitened on those parts that had been in the
mouth of the polyp (Fig. 1). Large prey species, especially
those with stiff skeletons (e.g. Protoreaster nodosus), that
were not able to escape the pull of the tentacles were only
partially eaten and were usually released with a single arm
missing. After digestion of the soft tissues, indigestible
parts were regurgitated through the mouth and fell onto the
sediment near the polyp (Fig. 1). Although spines of the
asteroid Acanthaster planci were also regurgitated, nothing
was found from Linckia laevigata.
Mean length of non-feeding polyps was 40 mm (N = 17), but
when feeding (N = 55) polyps extended up to 5 times normal
Page 3
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Bos et al.: Feeding biology of Paracorynactis hoplites
length (Fig. 1). One non-feeding polyp with a diameter of
90 mm and a length of about 45 mm stretched to 240 mm in
length when catching and enveloping a specimen of Linckia
laevigata (radius = 103 mm). The period from prey detection
to full ingestion usually lasted >1 h, but if conditions were
favorable to the polyp (i.e. small prey or poor traction on
sandy substrate), prey could be ingested in <1 min.
Symbiotic species. Some fishes took refuge among
the tentacles or hovered over the mouth of polyps of
Paracorynactis hoplites. Specimens of the cardinal
shes Apogon multilineatus, Apogon nigrofasciatus, and
Cheilodipterus quinquelineatus, and the gobies Eviota
pellucida and Trimma nasa swam among the tentacles of
the polyps, and appeared to contact them, apparently without
being adversely affected. Specimens of the dusky dottyback
Pseudochromis fuscus commonly swam about the column of
the polyp hiding underneath the crown of tentacles possibly
avoiding direct contact to the acrospheres. Less often, we
observed juveniles of the wrasse Halichoeres purpurescens
and the damselfi shes Plectroglyphidodon lacrymatus and
Fig. 5. Symbiotic shrimp Thor amboinensis among tentacles of
a polyp of Paracorynactis hoplites. Mouth of polyp is visible at
lower right (A. R. Bos).
Fig. 4. Entirely closed polyp of Paracorynactis hoplites where
tentacles are not visible (A. R. Bos).
Pomacentrus grammorhynchus near the tentacles without
actually touching the acrospheres, also apparently without
negative effects. The goby Trimma striata visited the column
of entirely closed polyps only (Fig. 4), when the risk of being
touched by tentacles was nil.
Specimens of the cleaner shrimps Periclimenes holthuisi
and Periclimenes lacertae lived among the tentacles, at an
abundance of one specimen per polyp. The shrimps Thor
amboinensis also lived among the tentacles (Fig. 5) with up
to fi ve individuals per polyp. Furthermore, two specimens of
the larger cleaner shrimp Stenopus hispidus were observed
to share a small crevice with a polyp of Paracorynactis
hoplites. S. hispidus antennae touching polyp tentacles did
not adhere to each other and did not appear to adversely
affect either party.
We regularly found injured polyps and sometimes just
some tissue of the mesenterial filaments. One polyp of
Paracorynactis hoplites survived repeated attacks by an
unknown predator during two months of observation, and
one polyp was eaten by two A. planci specimens.
DISCUSSION
Asteroids and echinoids appear to be major prey items of
Paracorynactis hoplites, because acrospheres easily attach
to these animals. Echinoids preyed upon were mainly
species with relatively short spines; this anatomy may
allow acrospheres to attach to soft tissue and explains why
the echinoids Diadema setosum, Diadema savignyi, and
Echinotrix calamaris, which have relatively long spines
(Coppard & Campbell, 2004), were unaffected. Excluding
the long-spined sea urchins, all echinoderms have surfaces
or relatively soft bodies to which acrospheres easily attach.
The acceptance of a nudibranch as prey (Table 1) may
suggest that all slow-moving, soft-tissue animals are potential
prey for polyps of P. hoplites. Only those with long spines
and smooth surfaces (e.g. shells) seem to be safe from
acrosphere attacks. However, only one species of shelled
mollusk was examined here, so further studies are needed
on reactions to a wider variety of potential prey items to
determine the diet specifi city of these corallimorpharians.
Many coral reef cnidarians are known to consume almost
any animal material that falls upon their oral disks, including
zooplankton (e.g. Fabricius & Metzner, 2004). The ability
of this corallimorpharian to consume large echinoderms is
interesting, especially consumption of the major cnidarian
predator Acanthaster planci, and may be a special trait of
this species.
Bos et al. (2008a) observed polyps of Paracorynactis
hoplites to prey upon specimens of Acanthaster planci with
maximum diameter of 250 mm. We found asteroids as large
as 340 mm consumed by polyps up to 170 mm diameter. The
polyps of P. hoplites did not feed differently and were not
adversely affected by consuming Acanthaster planci, which
is considered toxic to humans (Shiomi et al., 1985; Moran,
1990; Sato et al., 2008) and may also be toxic to some marine
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THE RAFFLES BULLETIN OF ZOOLOGY 2011
predators. Also, the echinoid Toxopneustes pileolus, known
to be toxic to fi shes (Frey, 1951), was eaten by the polyps
without being adversely affected.
Parts of prey items that had been in the mouths of polyps for
a short while, were whitened and showed signs of digestion,
possibly because their relatively stiff skeletons escaped the
pull of the tentacles, but they lost soft tissue from their
body. In areas where polyps of P. hoplites were abundant,
a relatively high proportion of specimens of the sea star
Protoreaster nodosus had shortened or missing rays (Bos et
al., 2008b). Thus polyps of P. hoplites may, together with
other predators, be responsible for high numbers of irregular
sea stars in the Davao Gulf (Bos et al., 2008c; Bos et al.,
2011). Moreover, polyps of P. hoplites were not observed
at the remote Tubbataha reefs in the Philippines and their
apparent absence or low density may have contributed to
a recent outbreak of Acanthaster planci in this UNESCO
world heritage site (Bos, 2010).
Although polyps of Paracorynactis hoplites appeared to
mainly prey on echinoderms, they may additionally be able
to prey on planktonic organisms. Other corallimorpharians
(Chadwick, 1991) and actinian sea anemones (Fautin et
al., 1995) prey on zooplankton, and the corallimorpharian
Amplexidiscus fenestrafer feeds on a wide range of food
items including zooplankton (Hamner & Dunn, 1980).
However, because polyps of P. hoplites were usually not
willing to take up more food after capturing prey (reduced
adhesiveness of acrospheres), the biomass uptake estimates
reported here may be fairly accurate, in that polyps were
satiated and did not otherwise feed. Feeding on zooplankton
may be of importance only when larger prey are not trapped
by these polyps.
Several fi sh species of different genera hovered near or
lived within the polyps of Paracorynactis hoplites without
adversely being affected. Anemones are known to host fi shes
and provide them with shelter and other benefi ts (Fautin &
Allen, 1997). Typical anemone fi shes are those of the genera
Amphiprion and Premnas (Fautin & Allen, 1997), but these
did not inhabit the polyps of P. hoplites. Also Hamner &
Dunn (1980) observed the relatively large corallimorpharian
Amplexidiscus fenestrafer not to be inhabited by these genera
and under laboratory conditions fi sh were even captured and
eaten. This may explain why none of the common anemone
shes were observed to inhabit polyps of P. hoplites.
Randall & Fautin (2002) observed other fi sh species than
anemone fi shes to associate with anemones, representing
some of the families that we observed to live about the
corallimorpharian polyps. These fi shes may be very cautious
in avoiding contact with the polyps or may have adjusted
to life with nematocysts by developing a mucus layer to
protect themselves against nematocyst attacks (Fautin,
1991). Anecdotal evidence suggested that the polyps of
Paracorynactis hoplites prey on fi sh, but such observations
were only done in aquaria. We fed a polyp with a dead
specimen of the scorpion fi sh Pterois volitans, which was
immediately ingested (personal observation). This confi rms
that P. hoplites accepts fi sh as prey.
The shrimps that live on the polyps of Paracorynactis
hoplites are cleaners of fish and other marine animals
(Becker & Grutter, 2004) and commonly live on anemones
(Guo et al., 1996). Some symbiotic shrimps collect trapped
planktonic organisms on anemone tentacles and remove
mucus secretions on their hosts’ columns (Fautin et al.,
1995). Some shrimps are highly selective in terms of their
association with hosts, but the shrimp Thor amboinensis is
considered a generalist symbiont with sea anemones (Guo
et al., 1996). Although the symbiotic shrimp Periclimenes
holthuisi is generally considered selective (Becker & Grutter,
2004), Khan et al. (2003) suggested that it does not exhibit
high host specifi city. The observation of P. holthuisi in polyps
of P. hoplites provides further evidence of lack of selectivity.
The circumtropical cleaner shrimp Stenopus hispidus does
not usually live symbiotically with anemones (Chockley &
Mary, 2003), but was observed to share a crevice with a
polyp of P. hoplites
without being affected.
ACKNOWLEDGEMENTS
This study was performed and partially fi nanced through
cooperation between the German Development Service
(DED) and the Davao del Norte State College. We greatly
acknowledge C. Fransen, J. Randall, and R. Winterbottom
for support with shrimp and goby identifi cations. Furthermore
we acknowledge D. Fautin for comments on an earlier
version of the manuscript. We thank the local government
units of Samal Island and the Department of Environment
and Natural Resources of Region XI, Philippines for their
continued support.
LITERATURE CITED
Becker, J. H. & A. S. Grutter, 2004. Cleaner shrimp do clean. Coral
Reefs, 23(4): 515–520.
Bos, A. R., 2010. Crown-of-thorns outbreak at the Tubbataha
Reefs UNESCO World Heritage Site. Zoological Studies,
49(1): 124.
Bos, A. R., G. S. Gumanao & F. N. Salac, 2008a. A newly
discovered predator of the crown-of-thorns starfi sh. Coral
Reefs, 27(3): 581.
Bos, A. R., G. S. Gumanao, J. C. E. Alipoyo & L. T. Cardona, 2008b.
Population dynamics, growth and reproduction of the Indo-
Pacifi c horned sea star, Protoreaster nodosus (Echinodermata;
Asteroidea). Marine Biology, 156(1): 55–63.
Bos, A. R., J. C. E. Alipoyo, L. T. Cardona, G. S. Gumanao & F.
N. Salac, 2008c. Population structure of common Indo-Pacifi c
sea stars in the Davao Gulf. UPV Journal of Natural Science,
13(Suppl.): 11–24.
Bos, A. R., G. S. Gumanao, M. M. van Katwijk, B. Mueller, M.
M. Saceda & R. P. Tejada, 2011. Ontogenetic habitat shift,
population growth, and burrowing behavior of the Indo-Pacifi c
beach star, Archaster typicus (Echinodermata; Asteroidea).
Marine Biology, 158: 639–648.
Page 5
250
Bos et al.: Feeding biology of Paracorynactis hoplites
Bruce, A. J., 1992. Two new species of Periclimenes (Crustacea:
Decapoda: Palaemonidae) from Lizard Island, Queensland,
with notes of related taxa. Records of the Australian Museum,
44: 45–84.
Chadwick, N. E., 1991. Spatial distribution and the effects of
competition on some temperate Scleractinia and Corallimorpharia.
Marine Ecology Progress Series, 70: 39–48.
Chockley, B. R. & C. M. St. Mary, 2003. Effects of body size
on growth, survivorship and reproduction in the banded coral
shrimp, Stenopus hispidus. Journal of Crustacean Biology,
23(4): 836–848.
Clark, A. M. & F. E. W. Rowe, 1971. Monograph of Shallow-Water
Indo-West Pacific Echinoderms. No. 690. British Museum
(Natural History), London. 238 pp.
Colin, P. L. & C. Arneson, 1995. Tropical Pacifi c Invertebrates.
Coral Reef Press, California. 296 pp.
Coppard, S. E. & A. C. Campbell, 2004. Taxonomic signifi cance
of spine morphology in the echinoid genera Diadema and
Echinothrix. Invertebrate Biology, 123(4): 357–371.
den Hartog, J. C., O. Ocaña & A. Brito, 1993. Corallimorpharia
collected during the CANCAP expeditions (1976–1986) in
the south-eastern part of the North Atlantic. Zoologische
Verhandelingen, 282(1): 1–76.
den Hartog, J. C., 1997. The sea anemone fauna of Indonesian coral
reefs. In: Tomascik, T., A. J, Mah, A. Nontji & M. K. Moosa
(eds.), The Ecology of the Indonesian Seas. Periplus Editions,
Singapore. Pp. 351–370.
Fabricius, K. E. & J. Metzner, 2004. Scleratinian walls of mouths:
Predation on coral larvae by corals. Coral Reefs, 23(2):
245–248.
Fautin, D. G., 1991. The anemonefi sh symbiosis: What is known
and what is not. Symbiosis, 10: 23–46.
Fautin, D. G. & G. R. Allen, 1997. Anemone Fishes and their Host
Sea Anemones. Western Australian Museum, Perth, Australia.
160 pp.
Fautin, D. G., C.-C. Guo & J.-S. Hwang, 1995. Cost and benefi ts
of the symbiosis between the anemoneshrimp Periclimenes
brevicarpalis and its host Entacmaea quadricolor. Marine
Ecology Progress Series, 129: 77–84.
Frey, D. G., 1951. The use of sea cucumbers in poisoning fi shes.
Copeia, 2: 175–176.
Froese, R. & D. Pauly, 2008. Fishbase. www.fi shbase.org (Accessed
Nov.2008).
Gosliner, T. M., D. W. Behrens & G. C. Williams, 1996.
Coral
Reef Animals of the Indo-Pacifi c. Sea Challengers, Monterey.
314 pp.
Guo, C.-C., J.-S. Hwang & D. G. Fautin, 1996. Host selection
by shrimps symbiotic with sea anemones: A fi eld survey and
experimental laboratory analysis. Journal of Experimental
Marine Biology and Ecology, 202(2): 165–176.
Haddon, A. C. & A. M. Shackleton, 1893. Description of some new
species of Actiniaria from Torres Straits. Scientifi c Proceedings
of the Royal Dublin Society (N.S.), 8: 116–131.
Hamner, W. M. & D. F. Dunn, 1980. Tropical corallimorpharia
(Coelenterata: Anthozoa): Feeding by envelopment. Micronesica,
16(1): 37–41.
Khan, R. N, J. H. A. Becker, A. L. Crowther & L. D. Lawn,
2003. Sea anemone host selection by the symbiotic saddled
cleaner shrimp Periclimenes holthuisi. Marine and Freshwater
Research, 54(5): 653–656.
Lieske, E. & R. Myers, 2002. Coral Reef Fishes; Indo-Pacifi c and
Caribbean. Princeton University Press, NJ, USA. 400 pp.
Moran, P. J., 1990. Acanthaster planci: Biographical data. Coral
Reefs, 9(3): 95–96.
Ocaña, O., J. C. den Hartog, A. Brito, & A. R. Bos, 2010. On
Pseudocorynactis species and another related genus from
the Indo-Pacifi c (Anthozoa: Corallimorphidae). Revista de la
Academia Canarias Ciencia, XXI(3–4): 9–34.
Randall, J. E. & D. G. Fautin, 2002. Fishes other than anemonefi shes
that associate with sea anemones. Coral Reefs, 21(2): 188–
192.
Sato, H., Y. Tsuruta, Y. Yamamoto, Y. Asato, K. Taira, K. Hagiwara,
S. Kayo, S. Iwanaga & H. Uezato, 2008. Case of skin injuries
due to stings by crown-of-thorns starfi sh (Acanthaster planci).
Journal of Dermatology 35: 162–167.
Shiomi, K., K. Itoh, H. Yamanaka & T. Kikuchi, 1985. Biological
activity of crude venom from the crown-of-thorns starfi sh
Acanthaster planci. Bulletin of the Japanese Society of Scientifi c
Fisheries, 51(7): 1151–1154.
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    • "For example, new Philippine fish species were recorded (Bos and Gumanao, 2013; Bos and Smits, 2013) and previously unknown fish (Motomura et al., 2001; Bos, 2014) and crab species (Husana et al., 2013) were taxonomically described. Moreover, the newly described polyps of the corallimorphian Paracorynactis hoplites (Oca~ na et al., 2010 ) were observed to prey intensively on the crown-of-thorns sea star Acanthaster planci (Bos et al., 2008Bos et al., , 2011), an ecological phenomenon so far only observed in the Davao Gulf. These unusual observations highlight the distinctiveness of biological populations in the Davao Gulf. "
    [Show abstract] [Hide abstract] ABSTRACT: Length–weight relationships (LWRs) of 139 coral reef and pelagic fish species (representing 34 fish families) were calculated based on 3806 individuals measured at local fish markets near the Davao Gulf in the southern Philippines during weekly visits between March 2009 and July 2011, as well as in June 2012. Fishes were caught with a variety of fishing methods, corroborated by abrasions and injuries. Forty-seven of 139 LWRs were firstly reported and new to science. The mean slope b of the LWRs was 3.035, indicating that the majority of studied species followed isometric growth. Standard length – total length relationships were calculated for all measured fish species. Additionally, standard length – fork length relationships are presented for 108 species. Moreover, fifteen new records of maximum fish length and weight are reported.
    Full-text · Article · Apr 2016 · Journal of Applied Ichthyology
    • "Earlier studies reported that coral skeletons of H. actiniformis may reach a maximum size of 21 cm (Hoeksema 1991b) representing an age of >40 years (Knittweis et al. 2009a). Because previous studies mention corallum size instead of polyp size, it is uncertain whether H. actiniformis corals in Davao Gulf grow larger than in other locations, as observed for the sea star Protoreaster nodosos (Bos et al. 2008a) despite high predation rates (Bos et al. 2008bBos et al. , 2011). The free-living corals of H. actiniformis occupy all kinds of environments and substrates from coastal habitats to offshore and from shallow reef flats and lagoons to deep sandy reef bases (Hoeksema 1991aHoeksema , 2012aHoeksema , 2012b). "
    [Show abstract] [Hide abstract] ABSTRACT: The free-living solitary mushroom coral Heliofungia actiniformis resembles sea anemones by having large, fleshy polyps with long tentacles, which provide shelter to symbiotic organisms. Commensal shrimps are well studied, but little is known about associated fish fauna. Therefore, the associated fauna of 118 coral polyps of H. actiniformis was examined at a depth range of 4–28 m in the Davao Gulf, Philippines. The distribution of associated fishes and symbiotic invertebrates highly depended on the size of the coral host: Large corals polyps (>18 cm) supported co-inhabiting fishes and commensal shrimps, medium-sized polyps (diameter 5–18 cm) hosted either fishes or shrimps, and small coral polyps (<5 cm) were uninhabited. Fifteen fish species, representing the Apogonidae, Gobiidae, Labridae, and Pomacentridae, were found. Among these, the gobies Eviota lachdeberei and E. rubriceps, and the labrid Oxycheilius celebicus were most common, making up for 77%of all fishes encountered. Total length of the fish ranged from 1 to 6 cm covering adult gobies and juveniles of the other families. Four species of commensal shrimps were hosted by the coral polyps. This study further constitutes the first record of brittle stars of the genus Ophiothrix (Echinodermata: Ophiuroidea) living among tentacles of H. actiniformis.
    Full-text · Article · Apr 2015 · Environmental Biology of Fishes
    • "In recent years however, new records of fishes have been observed in the Davao Gulf (Bos & Gumanao, 2013; Bos & Smits, 2013) and a new fish species Polydactylus longipes (Motomura et al., 2001) was described. Furthermore, unique ecological discoveries, such as a previously unknown corallimorph predator of the crown-of-thorns sea star Acanthaster planci (Bos et al., 2008; 2011b) and a commensal relationship between fishes and the mushroom coral Heliofungia actiniformis (Bos, 2012)—so far unique to the Davao Gulf—were reported. The present description of U. nigromarginatus, new species, further emphasises the biological and ecological distinctiveness of the Davao Gulf. "
    [Show abstract] [Hide abstract] ABSTRACT: The goatfish, Upeneus nigromarginatus new species, is described based on 5 specimens (151–196 mm) purchased at a fish market in Panabo City, Mindanao, Philippines. This species is diagnosed by the following counts and external morphology: dorsal fin rays (VIII, 9–10), pectoral fin rays (16), lateral line scales (36–37), total number of gill rakers (25–26), and anal fin rays (I–II, 6). When compared to congeners, U. nigromarginatus new species has a relatively deeper body (31.1–34.8% in SL vs. <30% in SL), shorter snout (7.1–9.0% in SL vs. >9.6 % in SL), and longer pectoral fin (27.7–29.1% in SL vs. <25 % in SL). Upeneus. nigromarginatus new species, has neither stripes on the body, nor bands on the caudal fin. However, a black band borders the distal edges of both the first and second dorsal fins, and at the posterior edge of the upper lobe of the caudal fin; hence the proposed common name ‘black-margined goatfish’. The posterior edge of the ventral caudal lobe has a white margin. The comparisons of a fragment of the Cytochrome C Oxidase Subunit I (COI; 28 specimens representing 10 Upeneus species) and 34 morphometric parameters (Principle Component Analysis; 56 specimens representing 5 genera and 12 mullid species) supported the description of U. nigromarginatus new species.
    Full-text · Article · Oct 2014 · The Raffles bulletin of zoology
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