A newly discovered predator of the crown-of-thorns starfish
ABSTRACT A large solitary polyp of the genus Pseudocorynactis (Corallimorpharia) was observed to prey on the crown-of-thorns starfish (Acanthaster planci), which itself has destroyed large areas of coral reefs by solely feeding on the polyps of reef-building corals. We observed Pseudocorynactis sp. to prey on echinoderms and to completely ingest starfishes, including the crown-of-thorns starfish, up to 25 cm in diameter. This newly discovered predator may play a key role in the ecology of crown-of-thorns outbreaks by controlling the juvenile and sub-adult populations of this starfish.
Full-textDOI: · Available from: Arthur R. Bos, Jul 28, 2015
- SourceAvailable from: Arthur R. Bos
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- "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 "
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.The Raffles bulletin of zoology 10/2014; 62:745-753. · 0.91 Impact Factor
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- "may play a role in offshore habitats (e.g. Bos et al. 2008c; Gaymer and Himmelman 2008), predation could have had a negative impact on the growth of small specimens in the shore habitats. Juvenile cohorts of Archaster typicus were observed between August and November, in both 2008 and 2009. "
ABSTRACT: Archaster typicus, a common sea star in Indo-Pacific regions, has been a target for the ornamental trade, even though little is known about its population biology. Spatial and temporal patterns of abundance and size structure of A. typicus were studied in the Davao Gulf, the Philippines (125°42.7′E, 7°0.6′N), from February 2008 to December 2009. Specimens of A. typicus were associated with intertidal mangrove prop roots, seagrass meadows, sandy beaches, and shoals. Among prop roots, specimens were significantly smaller and had highest densities (131 ind. m−2) between November and March. High organic matter in sediment and a relatively low predation rate seemed to support juvenile life among mangroves. Size and density analyses provided evidence that individuals gradually move to seagrass, sandy habitats, and shoals as they age. Specimens were significantly larger at a shoal (maximum radius R = 81 mm). New recruits were found between August and November in both 2008 and 2009. Timing of recruitment and population size frequencies confirmed a seasonal reproductive cycle. Juveniles had relatively high growth rates (2–7 mm month−1) and may reach an R of 20–25 mm after 1 year. Growth rates of larger specimens (R > 30 mm) were generally <2 mm month−1. The activity pattern of A. typicus was related to the tidal phase and not to time of day: Specimens moved over the sediment surface during low tides and were burrowed during high tides possibly avoiding predation. This is one of the first studies to document an ontogenetic habitat shift for sea stars and provides new biological information as a basis for management of harvested A. typicus populations. Electronic supplementary material The online version of this article (doi:10.1007/s00227-010-1588-0) contains supplementary material, which is available to authorized users.Marine Biology 01/2011; 158(3):639-648. DOI:10.1007/s00227-010-1588-0 · 2.39 Impact Factor
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- "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. "
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.The Raffles bulletin of zoology 01/2011; · 0.91 Impact Factor