Biology, Fishery and Trade of Sea Moths (Pisces: Pegasidae) in the Central Philippines
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Oryx Vol 38 No 4 October 2004 Biology, fishery and trade of sea moths (Pisces: Pegasidae) in the central Philippines Marivic G. Pajaro, Jessica J. Meeuwig, Brian G. Giles and Amanda C.J. Vincent Abstract Sea moths (family Pegasidae) are little- concentrated. Sea moths may be unsuited for heavy studied benthic fish, found throughout the Indo-Pacific. exploitation as they occur at low densities. Moreover, a Two species of sea moths, Pegasus volitans and female-biased catch could lower the effective population Eurypegasus draconis, are caught incidentally in illegal size, given the reported monogamy amongst sea moths. trawl gear in the Philippines and sold into the dried fish No population data were available for a complete conser- trade. Approximately 130,000–620,000 P. volitans and vation assessment, although divers surveyed did report 130,000 E. draconis were landed off north-western Bohol declines in their abundance. alone in 1996. An additional 43,000–62,000 sea moths (predominantly P. volitans) were caught live for the aquarium trade. Catch per unit effort for P. volitans was Keywords Aquarium trade, bycatch, Eurypegasus double that of E. draconis, probably because of its draconis, Pegasidae, Pegasus volitans, Philippines, sea occurrence in shallower waters where fishing effort was moths, traditional medicine. Introduction seahorses, pipefishes and seadragons (family Syngna- thidae) and of the ghost pipefishes (family Solenosto- Despite the recognition that most of the world’s fisheries midae) (Pietsch, 1978). In a taxonomic revision, Palsson are fully or overexploited (FAO, 2000) relatively little & Pietsch (1989) described five species in two genera: attention has been paid to fisheries for non-food con- Pegasus laternarius, P. volitans, P. lancifer, Eurypegasus sumption. The impacts of the demand for marine animals draconis and E. papilio. The few studies on sea moth for traditional medicines and tonic foods, ornamental ecology and behaviour have suggested that sea moths display, bait, curiosities, cosmetics, chemicals, leather, possess some characteristics commonly associated with and other uses are not well known. However, over- species unsuited to heavy exploitation, i.e. low popula- exploitation of fishes for non-food use is now causing tion densities and established long-term pair bonds of concern, particularly for some of the species used as one male and one female that mate repeatedly (Pegasus traditional medicines (Vincent, 1996, 1997), aquarium lancifer, Kuiter, 1985; Eurypegasus draconis, Herold & fishes (Wood, 1992, 2001; Sadovy & Vincent, 2002) and Clark, 1993). Both taxa are categorized as Data Deficient baits (Blaber et al., 1994). on the 2003 IUCN Red list (IUCN, 2003). Sea moths (family Pegasidae) comprise a poorly understood taxon of fishes that is commercially exploited Millions of sea moths are sold for traditional medicine for traditional medicines and aquarium display (Vincent, each year in China and Hong Kong alone, with supplies 1997). Inhabitants of temperate and tropical coastal zones coming from China, Vietnam and other areas in throughout the Indo-Pacific (Palsson & Pietsch, 1989), South-east Asia (Vincent, 1997). Dried sea moths are sea moths may be the primitive sister group of the used primarily as treatment for respiratory ailments, in particular childhood bronchial infections, and are also thought to cure lymph node and thyroid disorders, breast cancer, goitres and diarrhoea following measles Marivic G. Pajaro1 (Corresponding author) Project Seahorse-Haribon Foundation for the Conservation of Natural Resources, Cebu, Philippines. (Vincent, 1997). Live sea moths are sold for ornamental E-mail [email protected] display but volumes are uncertain; the Global Marine Jessica J. Meeuwig, Brian G. Giles1 and Amanda Vincent1 Project Seahorse, Aquarium Database records limited imports to the Department of Biology, McGill University,1205 Ave. Dr. Penfield, Montréal, United Kingdom and the USA (UNEP-WCMC, 2002) but Québec H3A 1B1, Canada. sea moths do not appear in a comprehensive list of 1Present address: Project Seahorse, Fisheries Centre, The University of aquarium fish species being traded around the world British Columbia, 2204 Main Mall, Vancouver, BC V6T 1Z4, Canada. (Wood, 2001). Their use in aquaria is probably limited, Received 28 October 2002. Revision requested 14 October 2003. with interest mainly because of the oddity of their shape Accepted 19 January 2004. rather than any attractive colouration or ornamentation. 432 © 2004 FFI, Oryx, 38(4), 432–438 DOI: 10.1017/S003060530400081X Printed in the United Kingdom Downloaded from https://www.cambridge.org/core. IP address: 170.106.202.58, on 03 Oct 2021 at 00:54:34, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S003060530400081X Sea moth biology, fisheries and trade 433 The Philippines is among the countries catching and to detail and estimate sea moth bycatch in small-scale potentially exporting sea moths (Vincent, 1997). Two fisheries. We also present information on the trade of sea species, P. volitans and E. draconis, have been reported moths and the economic importance of this trade. from the Philippines (Palsson & Pietsch, 1989), and P. volitans was documented in trawl bycatch in the Methods Visayan area of the central Philippines (Ordonez, 1981). A limited trade survey in 1995 reported only that an Bycatch monitoring exporter in Cebu abandoned plans to export sea moths We monitored sea moth bycatch in trawl fisheries at two because of the low prices obtained for P. volitans in sites in Bohol province, along the Danajon Bank, Banacon traditional medicine (Vincent, 1997). village (Getafe municipality) and Malinguin village (Bien Pegasus volitans is a slender, swift-swimming sea moth, Unido municipality) (Fig. 1). Bohol is located in the reported to reach a maximum length of 180 mm (Palsson central Visayas region of the Philippines which, along & Pietsch, 1989). Inhabitants of muddy and sandy with the adjacent Panay Islands, once accounted for 50% bottoms, they are often found in association with prawns of all commercial fish caught in the Philippines (Smith (Conlu, 1986). They typically live at 2–30 m depth, but et al., 1980). The fishers we monitored employed two have also been found on the surface and as deep as 73 m types of illegal small-mesh nets: otter trawl (palakaya) (Palsson & Pietsch, 1989). and modified Danish seine gear (liba liba) (for gear Eurypegasus draconis is a wider-bodied, shorter species, descriptions, see BFAR, 1988). with a maximum recorded length of 77 mm (Palsson & Samples of P. volitans were obtained from May 1996 Pietsch, 1989). These fish have been collected at depths to January 1997 from a small-scale grouper farmer on as shallow as 3 m, but are more commonly found in nearby Jandayan Island, who purchased all daily bycatch deeper water (37–91 m) (Palsson & Pietsch, 1989; Herold from one Banacon otter trawler to use as feed. Samples & Clark, 1993). E. draconis generally inhabits coarser of E. draconis were obtained from a fisher using Danish sediment areas (sand, gravel and shell-rubble) (Palsson seine gear in Malinguin, who set aside daily sea moth & Pietsch, 1989), where they conceal themselves by bycatch, from November 1995 to March 1996. While he mimicking a piece of broken shell (Kuiter, 1985). These sometimes caught both species, only E. draconis were fish may also occur among seagrass or patches of corals kept. Specimens were placed into labelled individual (Palsson & Pietsch, 1989; Herold & Clark, 1993). plastic bags and preserved with 10% formalin. Here we report on the distribution and biology of these Standard length (mm) and weight (g) were taken from two species of sea moth in the Philippines and use data fresh P. volitans specimens, while E. draconis specimens obtained from direct monitoring and trade surveys preserved in 10% formalin were measured but not Fig. 1 (A) Map of the Philippines and (B) the Danajon Bank (Northern Bohol) showing trade survey areas and study locations. © 2004 FFI, Oryx, 38(4), 432–438 Downloaded from https://www.cambridge.org/core. IP address: 170.106.202.58, on 03 Oct 2021 at 00:54:34, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S003060530400081X 434 M. G. Pajaro et al. weighed. Preserved specimens of both species with average weight of P. volitans from catch monitoring. intact internal organs were later sexed by gonad dis- Total live catch was estimated by extrapolating the section. Some specimens, not preserved immediately reported volumes purchased by an exporter in Manila to after capture, were impossible to sex because of tissue all known exporters, accounting for the primary buyer- damage. reported percent mortality between catch and sale to exporters. Trade studies Results We conducted trade studies focusing on two markets: dried sea moths destined for use as traditional medicines Distribution and habitat and live sea moths collected as aquarium fishes. Casual Surveys suggested that both species of sea moths are and semi-structured interviews were conducted with found throughout the Philippines (Fig. 1). Fisher reports, fishers and trade participants (n = 39) around the Philip- supplemented with museum specimens (Palsson & pines in 1995 and 1996. In the absence of an accurate list Pietsch, 1989), reported both species in Batangas, Bohol, of fishers or buyers, survey participants were located Cavite,