SHORT COMMUNICATION The first report of Vibrio harveyi infection in the sea horse Hippocampus kuda Bleekers 1852 in the Philippines Eleonor A Tendencia Aquaculture Department, Southeast Asian Fisheries Development Center, Tigbauan, Iloilo, Philippines Correspondence: E A Tendencia, Aquaculture Department, Southeast Asian Fisheries Development Center,Tigbauan 5021, Iloilo, Philippines. E-mail: sidgigit@iloilo.net Vibriosis is a common bacterial disease in marine or- ganisms. The ¢rst signs of vibriosis are usually anor- exia and darkening of the whole ¢sh.Vibriosis usually occurs in the warm summer months when the sa- linities and organic loads are high. Ortigosa, Esteve and Pujalte (1989) reported that the abundance of Vibrio harveyi and V . mediterranei were positively cor- related with temperature, whereas V. pelagius counts showed negative correlation.Vibrio vulni¢cus was iso- lated from seawater in Korea during the month of Au- gust only when the water temperature and chemical oxygen demand (COD) were high, but the pH and salinity low (Kim, Lee, Lee & Lee 1990). Isolation rate of V. cholerae increases with increased temperature and organic pollution (Redacli¡, Hornitzky, Carson, Petersen & Zelski 1993). Vibrio alginolyticus was found in the water and attached to the copepod Tigriopus ful- vus during the warmest month (Carli, Pane, Casareto, Bertone & Pruzzo1993). Sea horses are used in Asian countries in tradi- tional Chinese medicines. They are also popular in the global aquarium trade. Approximately, 20000000 sea horses are collected from the wild annually (Vincent 1996). In some areas, a 50% de- cline in the population over the last 5 years has been reported (Hilomen-Garcia 1999). Due to increasing demand and the potential extinction of sea horses, the Aquaculture Department of the Southeast Asian Fisheries Development Center (SEAFDEC) in Iloilo, Philippines undertook breeding and seed production of the sea horse, Hippocampus kuda Bleekers 1852. In 1999, sea horses 3^4 months old and 3^5g in weight that were cultured in 1-tonne ¢breglass tanks at SEAFDEC and fed with Ascetes sp. twice daily, ex- hibited increased mortality. Less than 1% daily mor- tality was observed. Clinical signs included a loss of skin colour from black to milky white particularly in the mid and upper body portion. Some animals exhib- ited light brown to orange discolouration. A¡ected sea horses appeared weak and slow moving. The ab- dominal region was also depressed in some cases and a pale kidney was observed after dissection. Six sea horses displaying symptoms were exam- ined for bacteria. Samples for bacteriological analysis were taken from the skin and kidney and were sub- sequently inoculated onto nutrient agar (NA) (BBL) and thiosulphate citrate bilesalt sucrose agar (TCBS) (BBL) plates. Plates were incubated for 24 h at 30 1C. On NA, luminous bacteria were observed in the skin and/or kidney samples from the sea horses. On TCBS, yellow colonies were the dominant bacterial colony type. A total of 12 representative colonies from the two organs of the six sea horses were chosen. The isol- ates were puri¢ed on NA and identi¢ed using con- ventional biochemical tests described by MacFadden (1976) and West and Colwell (1984). The isolates were identi¢ed based on the scheme of Baumann and Schubert (1984). Eleven of the chosen isolates were identi¢ed as V. harveyi and one was identi¢ed as V. splendidus biovar1. The characteristics and identi¢ca- tion of the isolates are presented in Table 1. The sens- itivity of the isolates to some antibiotics was also determined using the disc di¡usion method de- scribed by Finegold and Martin (1982). The antibiotics tested were oxytetacycline (OTC),30 mg; oxolinic acid (OXA), 2 mg; chloramphenicol,30 mg and furazolidone, Aquaculture Research, 2004, 35, 1292^1294 doi: 10.1111/j.1365-2109.2004.01109.x 1292 r 2004 Blackwell Publishing Ltd