1 Conservation of the critically endangered endemic Malaysian black fighting fish 2 Betta persephone Schaller (Teleostei: Osphronemidae): a brief review 3 4 Kok Gan Chan1, * 5 6 1 Division of Genetics & Molecular Biology, Institute of Biological Sciences, 7 Faculty of Science, University of Malaya, 50603 Kuala Lumpur 8 9 10 *Corresponding author: Kok-Gan Chan 11 Institute of Biological Sciences (Division of Genetics and Molecular Biology), 12 Faculty of Science, University of Malaya, 50603 Malaysia. 13 Tel: +603-79675162, Fax: +603-79674509. Email: [email protected] s t 14 n i r 15 ABSTRACT P 16 Malaysian black fighting fish Betta persephone Schaller (Teleostei: Osphronemidae) e r 17 is economically and ecologically important fish in South East Asia notably in P 18 Malaysia. The locals keep this fish as ornemental fish as well as biocontrol for 19 mosquitoes larvae. But due to rapid deterioriration of its habitats and economy 20 activities, hence this fish population is decreasing at an alarming level. If this goes 21 unnoticed, the fish may face the risk of extinction. In this review, the author 22 performed a systematic approach to analyse the issues, and propose the ways 23 forward to preserve and sustain this fish both in captivity as well as in its natural 24 habitat. 25 26 KEYWORDS 27 Aquatic, Betta, fighting fish, fish ecology, fresh water fish, Osphronemidae, 28 sustainability 29 30 INTRODUCTION 31 Betta is a freshwater fish from the family Osphronemidae popularly known 32 as fighting fish or locally know as “Ikan Laga” in Malaysia. They are found in a 33 variety of freshwater habitats from the clearwater hillstreams, freshwater swamps 34 and peat swamp forests to the harsh man-made environment of canals and paddy 35 fields. Fighting fish are one of the popular ornamental fish, particularly in the Asia 36 region. Aquarium fish industry is a multi-million dollar global industry. To illustrate, 37 FAO 1998 statistics reported that the value of ornamental fish world export was 38 US$174 million and import value of US$257 million, with the developing countries 39 contributing about two thirds of the total export value (Bartley 2005). Malaysian 40 contribution in ornamental fish trade has rapidly increased from RM 70.4 million 41 (approximate US$ 18 million) in 1998 to RM 735 million (approximate US$ 221 42 million) in 2008 (DOF 1998 & 2008). PeerJ PrePrints | https://dx.doi.org/10.7287/peerj.preprints.1048v1 | CC-BY 4.0 Open Access | rec: 8 May 2015, publ:1 8 May 2015 43 The small black fighting fish Betta persephone (Osphronemidae) from Johore 44 (Malaysia) was first described in 1986 by Schaller (Schaller 1986). The holotype 45 (ZFMK 14226) was deposited at Zoologisches Forschungsmuseum Alexander 46 Koenig, Bonn, Germany. The specimen was from Air Hitam, with minimal locality 47 description – “Asian highway no. 2, 3 km north of Ayer Hitam, Malaysia, 20 Feb 48 1985” (Herder 2010). 49 The B. persephone is placed under the “species group” of Betta coccina 50 group with eight members, including 5 members from Malaysia which all of them 51 are restricted to peat swamp forests. The “species group” is based on as assemblage 52 of species sharing a set of diagnostic characters and the group may not be a 53 monophyletic lineage. The species groups have been well documented (Tan & Ng 54 2005). s 55 B. persephone is endemic to Peninsular Malaysia, restricted to peat-swamp t 56 forest in Air Hitam area, south-western part of Johore. Beside the occurrence data in n i 57 peat swamp forests, surprisin there is a dire lack published materials on its ecology r 58 and biology of this highly threatened species. After two and a half decades of its P e 59 discovery, B. persephone is now classified as Critically Endangered (CR) under the r 60 IUCN Red List of Threatened Species (IUCN 2009). In a recent review of P 61 conservation of fishes in Malaysia, it is classified as highly threatened which is a 62 category below local extinction (Chong 2010). The loss of habitats of peat swamp 63 forest within its distribution range is possibly the critical reason of its decreased 64 population. Despite numerous surveys and attempts to relocate the population, but all 65 were unsuccessful. This is mainly due to habitat degradation and destruction of its 66 previously known collection sites. B. persephone was last collected from Ayer Hitam 67 area in 2006 (unpublished data). Their rapid decline and scarcity is a major concern 68 for the conservation of this species as it is an endemic stenotopic black water species 69 with very narrow distribution, only found in a single area in southwestern Johore. 70 This purpose of this paper is to document some basic ecological information 71 and molecular characterization of the species from the wild stock in the event of 72 extinction of the species from its natural habitats. Useful conservation measures will 73 be discussed. 74 75 B. persephone habitats 76 After surveying the various locations, both within the AHFR from all the four 77 boundaries of the Air Hitam Forest Reserve and also outside the reserve, we 78 managed to discover B. persephone in a sampling site outside the northern boundary 79 of the Air Hitam Forest Reserve (Figure 1). The site is a fragmented remnants peat 80 swamp forest. The surrounding areas are mixed agricultural land, mainly dominated 81 with small palm oil estates interspersed with fruits orchard and vegetable farms. It 82 should be noted that the last known B. persephone site was also located outside the 83 forest reserve (see Figure 1). The habitat where the fish was caught is a typical of B. 84 persephone habitat, closed canopy peat swamp forest, relatively intact. They prefer PeerJ PrePrints | https://dx.doi.org/10.7287/peerj.preprints.1048v1 | CC-BY 4.0 Open Access | rec: 8 May 2015, publ:2 8 May 2015 85 small stagnant pool of water with plenty of leaf litter. Unlike their sympatric species 86 Betta bellica which swim in the open water column, B. persephone is shy peaceful 87 fish, usually hide under the leaf litter. 88 During the survey, the water condition was found low in dissolved oxygen 89 1.29 – 2.00 mg/L (16.0 – 24.5 % saturation), and acidic (pH 3.86 – 4.06) with 90 conductivity of 55 –73 µS/cm and water temperature ranges from 25.9 – 26.1°C in 91 the late morning. The water condition is typical of inland concentrated blackwater 92 characteristics. The dissolved oxygen of the inland concentrated blackwater can be 93 as low 0.36 mg/L, especially during dry season when the water flow is low or when 94 it is stagnant (Lee 2003). The low pH is the characteristic of concentrated blackwater 95 of the peat swamp forests (Ng 1994; Lee 2003; Noraini 2010). The conductivity is 96 comparable to those of the peat swamp forest adjacent to oil palm plantation, s 97 averaging between 42.07 – 98.72 µS/cm in Sarawak (Noraini 2010) and much lower t from those of Selangor (Peninsular Malaysia) ranging from 112 – 737 µS/cm (Lee n 98 i r 99 2003). However, the conductivity was higher than of the undisturbed peat swamp P 100 forest in Brunei which ranges between 20 – 50 µS/cm (unpublished data). The higher e conductivity may be attributed to the anthropogenic activities and some nutrients r 101 P 102 runoff from agricultural activities. 103 PeerJ PrePrints | https://dx.doi.org/10.7287/peerj.preprints.1048v1 | CC-BY 4.0 Open Access | rec: 8 May 2015, publ:3 8 May 2015 104 PAGOH North-South Expressway Proposed s t extension of n AHFR i r P e r Air Hitam Forest Reserve P (AHFR) 105 106 Figure 1. The location of Air Hitam Forest Reserve and the 107 location of the current occurrence (black triangle) 108 and one of last known occurrence of Betta 109 persephone (black diamond). Both the locations 110 were located outside the forest reserve. 111 112 Loss of peat swamp forest and ecological risk of extinction 113 One of the main concerns is the current B. persephone site is located outside 114 the forest reserve which means that there is no protection for its habitat. During the 115 survey, we found that the land has been recently allocated to the locals by the local 116 state authorities into small land titles (i.e. one acre to each eligible individual). 117 However, we were not able to confirm the actual status of the land or the acreage of 118 the land conversion. The loss of intact peat swamp forest habitats can spell doom to PeerJ PrePrints | https://dx.doi.org/10.7287/peerj.preprints.1048v1 | CC-BY 4.0 Open Access | rec: 8 May 2015, publ:4 8 May 2015 119 this endemic species which is listed as Critically Endangered (CR) under IUCN Red 120 List of the Threatened Species. 121 122 The loss of peat swamp forests has been very drastic and alarming. 123 Peninsular Malaysia used to have a cover of 0.67 million ha in 1981 and within a 124 decade has lost 50% to merely 0.34 million ha due to loss from logging, aquaculture, 125 agriculture, industries and human settlements (UNDP 2006). Only 67% of the 126 remaining peat-swamp forests are designated as permanent forest reserves (PFR) by 127 the Federal government, while the remainder is state land forests which could be 128 easily converted for other land use. However, logging is allowed in the PFR on a 129 sustainable basis, and the logging activity have been reported to be detrimental to 130 peat swamp fishes (Lee 2003).