Digenetic trematodes are widespread among mud snails (Hydrobiidae) living in coastal lagoons and estuaries, but knowledge is generally lacking on their impact on these host organisms. We examined the survival rates of infected and non-infected experimental populations of two mud snail species, Hydrobia ventrosa (Montagu) and Hydrobia neglecta Muus, exposed to desiccation, freezing and anoxia in the laboratory. Our experiments indicated that non-infected groups of both species had similar survival rates after being subjected to desiccation and anoxia, whereas H. ventrosa survived freezing better than H. neglecta. However, infected groups of H. neglecta specimens subjected to desiccation showed significantly lower survival rates than non-infected groups. Infected and non-infected snails of both species exposed to freezing and anoxia exhibited similar survival rates. The possible mechanisms by which parasites influence their hosts are discussed. It is unlikely that the parasites in the present case mediate the coexistence of the two Hydrobia-species, because the snail with the highest reproductive effort -H. neglecta -showed lower infection rates in situ than its congener H. ventrosa.

This study aimed to examine the development of seaweed in Takalar District. The method used in this study is a survey and direct interview using questionnaires and FGD (Focus Group Discussion) to various parties and stakeholders related to the production and development of seaweed. The study location is located in Takalar District Results The study of strategies for various aspects of development and productivity of seaweed can be applied with; 1) Expanding cultivation land and innovation and developing the latest cultivation technology, 2) Conducting gradual extension of seaweed farmers, 3) Development of seaweed processing industries, 4) Building nurseries to meet the availability of good quality seeds, 5) Conducting Training and Assistance in implementing the latest technological innovations, 6) Providing venture capital assistance and system improvement Warehouse Receipt 7) Scheduling seaweed cropping patterns, 8) Building and developing seaweed storage warehouses, 9) Developing new technologies to overcome pests and diseases in plants seaweed, 10) Conducting seaweed farmer institutional strengthening to strengthen the bargaining position of seaweed prices 11) Improving the quality of seaweed

Seaweed is an important export commodity, making a substantial contribution to the income of coastal fish farmers in South Sulawesi, Indonesia. In particular, kappa carrageenan from Kappaphycus alvarezii is a widely used raw material in the pharmaceutical, food, and other industries and Indonesia is currently ranked as the top carrageenan-producing sea weed exporting country. Crop failure in seaweed cultivation is mostly caused by disease. In Kappaphycus alvarezii crops, ice-ice and epiphytic diseases have been identified, and more information is required to develop ways to control these diseases. This study aimed to investigate these diseases and their effect on growth and carrageenan quality in this species. The research was conducted in Malosoro Bay, Jeneponto District, South Sulawesi. Observations on the effect of disease on seaweeds grown using a long line culture method were conducted "insitu". Observation on carrageenan quality was conducted in the laboratory using a Completely Randomized Design. Growth and carrageenan content data were analyzed using a one way ANOVA. The results showed that presence of these diseases had a significant effect (P<0.05) on K. alvarezii growth, thallus strength and integrity, and carrageenan content.Keywords Carrageenan; Ice-ice; Disease; Epiphytic; Kappaphycus alvarezii; Seaweed BackgroundIndonesia is the leading seaweed producer in the world (FAO, 2016). Currently, the seaweed export from Indonesia has reached 169,113 tons per year or equivalent to USD$ 134,348,000 (Statistics Department of Commerce, 2012) where Sulawesi contributes approximately 60% of the volume. The cultured seaweed in Sulawesi is dominated by Kappaphycus spp. foremost K. alvarezii.Presently, there are several problems faced by the seaweed farmers in Sulawesi that the cultured seaweed has infected by diseases for example epiphyte parasites and ice-ice diseases. Besides that, the quality of the seed is also gradually decreased due to multiple used of the thallus. These conditions led to the production decline and even threatened to harvest failure (Afrianto and Liviawati, 1993).Post-harvest handling is still constrained in conjunction with the drying mainly in the rainy season and drying technique is simple and does not consider the quality of seaweed on the results of the process of drying on the sand, roadside and other techniques that do not support to find the products seaweed quality. Seaweed processing is also just up the seaweed processing of raw materials or semi-finished namely dried seaweed, which is processed into chips and semi refine carrageenan, then exported.The low attention to make a plan in order to increase the maximum added value as a plan activities that make an assessment at the stage of implementation of an activity from upstream to downstream or from aquaculture production to production-ready material. Seaweed production is currently based solely on a two (2) genus that is Kappaphycus spp. reared in sea and Gracillaria spp. reared in brackish-water ponds which both the ge...

Salah satu yang menyebabkan kegagalan budidaya rumput laut Kappaphycus alvarezii  yaitu terserangnya penyakitice – ice . Penyakit ice-ice merupakan penyakit yang umum terjadi pada rumput laut kappaphycus  dengan gejalaterjadinya pemutihan pada bagian thallus  dan penyakit ini dapat menyebabkan kematian massal pada produksirumput laut kappaphycus alvarezii . Salah satu cara yang dapat dilakukan untuk menganalisa bagian thallus  rumputlaut Kappaphycus alvarezii  yaitu uji histopatologi. Penelitian ini bertujuan untuk mengetahui perubahan bentuksel pada kondisi jaringan thallus  rumput laut K.alvarezii  yang terserang penyakit ice- ice  menggunakan metodehistopatologi. Pengambilan sampel rumput laut yang digunakan jenis Kappaphycus alvarezii  varietas coklat danhijau dengan 1 titik masing – masing varietas. Sampel rumput laut terdiri atas 2 sampel yaitu bagian thallus  yangterserang penyakit ice-ice  dan bagian thallus  tanpa gejala ice-ice . Sampel berumur 15 hari. Sampel yang dipilihuntuk pemeriksaan, dipotong setebal 0,5 - 1 cm. Sampel dimasukkan kedalam botol sampel untuk difiksasi ± 1minggu, yang berisi formalin 10%.Tahapan pembuatan preparat histopatologi terdiri atas fiksaksi, dehidrasi,clearing , impregnasi , embedding , cutting , staining , dan pemeriksaan dibawah mikroskop. Penelitian ini dianalisissecara dekskriptif kualitatif dengan melakukan pengamatan gambar histopatologi pada jaringan rumput laut K.alvarezii . Jaringan thallus  yang yang terserang penyakit ice-ice  mengalami perubahan bentuk sel, bagian lapisanluar terlihat tidak utuh, hancur, sehingga mengalami kematian sel dan bagian korteks dalam dinding sel terlihattidak teratur dan renggang, tidak terbentuk bulat atau lonjong, sebagian sel mengecil. Jaringan thallus  yang tidaknormal mengalami gejala Hipoplastik (terhambatnya atau terhentinya pertumbuhan sel) dan Nekrotik (kematiansel).Kata kunci : Kappaphycus alvarezii, penyakit ice – ice, Histopatologi, Hipoplastik, Nekrotik

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