Identification of lower fungi isolated from larvae of mangrove crab, Scylla serrate, in Indonesia

Abstract

Since 1992, seed production of mangrove crab, Scylla serrate, has been attempted at the Gondol Research Station for Coastal Fisheries, Bali, Indonesia. During the production process, almost all of the larvae have died due to fungal infection. Fungi isolated from the larvae with fungal infection were classified into three species in the order Lagenidiales:Lagenidium callinectes, Haliphthoros milfordensis and Halocrusticida baliensis sp. nov. based on detailed morphological characteristics. The effects of temperature, pH and mineral content of the water on their growth were also examined. Seed production of the mangrove crab, Scylla serrate Forsskal, is an important industry in Indonesia. A serious problem facing this industry is fungal diseases, due to fungi belonging to the order Lagenidiales, which cause high mortality in the eggs and zoeal larvae. Fungal diseases in crabs caused by the fungi of the order Lagenidiales have been previously reported. In the genus Lagenidium, L. callinectes Couch has been reported from blue crab, Callinectes sapidus Rathbun (Couch, 1942; Bahnweg and Gotelli, 1980), and swimming crab, Portunus pelagicus (Nakamura and Hatai, 1995a). L. scyllae Bian et el. (Bian et. el., 1979) and L. thermophilure Nakamura et el. (Nakamura et el., 1995) have been isolated from mangrove crab, Scylla serrate. In the genus Haliphthoros, Hall milfordensis has been reported from swimming crab, Portunus pelagicus (Nakamura and Hatai, 1995a Halocrusticida hamanaensis and Halo. okinawaensis were formerly identified as fungi in the genus Atkinsiella. Atkinsiella dubia was also reported from the mantle of abalone, Haliotis sieboldii Reeve (Nakamura and Hatai, 1995a).In 1997, fungal diseases occurred in the eggs and zoeae of the mangrove crab S. serrate at the Gondol Research Station. The mortality rate reached almost lO0~ in the larvae. The infected larvae were whitish in color and filled with numerous aseptate hyphae. In this paper, the morphological and physiological characteristics of three strains of fungi isolated from the larvae of the mangrove crab with fungal infections were studied. Material and Methods Isolation and identification Zoeae of the mangrove crab,Scylla serrate Forsskal, which were produced at the hatchery of the Gondol Research Station for Coastal Fisheries, Bali, Indonesia, were reared at 25-27~ in a tank and fed with rotifers, Branchionus plicatilis MLiller, and brine shrimp, Artemia saline Linnaeus. The infection occurred in the zoeae in July 1997. Zoeae from the tank were observed under the microscope.If fungal elements were present, we attempted to isolate them using PYGS (1.25 g of Bacto peptone, 1.25 g of Bacto yeast extract, 3 g of glucose, and 12 g of Bacto agar and 1,000 rn/of seawater) containing streptomycin sulphate and ampicillin, each at a concentration of 500 f~g/ml, to retard bacterial growth. The agar plates were incubated at 25~ for 5-7 d. After fungal colonies developed on the agar plates, each one was transferred onto fresh PYGS agar to make a pure culture. The f...

Haliphthoros milfordensis isolated from black tiger prawn larvae (Penaeus monodon) in Vietnam

“…The range of optimal temperature for hyphal growth of H. milfordensis NJM 0131 was 25°-30°C, which was similar to that of H. milfordensis as previously reported by Vishniac (1958), Hatai (1982), Nakamura and Hatai (1995), and Hatai et al (2000). The isolate NJM 0131, however, grew even at 40°C and an isolate of H. philippinensis reported by Hatai et al (1980) also grew at 36.3°C.…”

“…Haliphthoros milfordensis has been reported as a parasite of various marine crustaceans (Nakamura and Hatai 1995;Hatai et al 2000). The fungus isolated from the black tiger prawn Penaeus monodon with fungal infection in this study showed low pathogenicity to the larvae of the swimming crab Portunus trituberculatus in Japan.…”

“…Later, the fungus was reported on the surface of the alga Enteromorpha sp. (Fuller et al 1964), juveniles of the American lobster Homarus americanus Edwards (Fisher et al 1975), the mantle, foot, and epipode of abalone, Haliotis sieboldii Reeve (Hatai 1982), zoeae of the mangrove crab Scylla serrata Forsskal (Hatai et al 2000), and zoeae of a marine crab, Portunus pelagicus Linnaeus (Nakamura and Hatai 1995). Haliphthoros milfordensis has been also reported from some prawns, the white shrimp Penaeus setiferus Linnaeus (Tharp and Bland 1977) and the kuruma prawn Penaeus japonicus Bate (Hatai et al 1992).…”

Molecular phylogeny of an unidentified Haliphthoros-like marine oomycete and Haliphthoros milfordensis inferred from nuclear-encoded small- and large-subunit rRNA genes and mitochondrial-encoded cox2 gene

“…To date, the genus Haliphthoros contains two species, H. milfordensis Vishniac (type species;Vishniac 1958) and H. phillippinensis Hatai et al, that were distinguished on the basis of morphological differences associated with zoosporogenesis and zoospore release (Hatai et al 1980). Because Haliphthoros species have been frequently isolated from diseased organisms and are considered to be serious pathogens of economically important marine crustaceans, they were studied so they could be characterized both morphologically and physiologically (Nakamura and Hatai 1995;Hatai et al 2000;Diggles 2001;Chukanhom et al 2003). Haliphthoros has been isolated from all over the world, and nearly all the isolates have been identifi ed as H. milfordensis.…”

A new peronosporomycete, Halioticida noduliformans gen. et sp. nov., isolated from white nodules in the abalone Haliotis spp. from Japan

“…In artifi cial seawater, the four isolates form the fragments by constricting protoplasm in the hyphae such as in the genus Haliphthoros, but the protoplasm constriction was weaker, and fragments were longer, with smaller space between them, than that of Haliphthoros. The fungi of the genus Haliphthoros form only one discharge tube from a zoosporangium (Vishniac 1958;Hatai et al 1980Hatai et al , 1992Hatai et al , 2000Nakamura and Hatai 1995a;Chukanhom et al 2003), but the four isolates do have one or more discharge tubes from each zoosporangium. As a result, we name them Halioticida noduliformans gen. et sp.…”