Electronic Theses and Dissertation

Infestasi ektoparasit pada udang vannamei (Litopenaeus vannamei) telah banyak dilaporkan, namun informasi kuantitatif mengenai perbedaan tingkat serangan pada sistem budidaya intensif dan semi intensif di pantai Barat Aceh masih terbatas. Penelitian ini bertujuan untuk menentukan prevalensi, intensitas, dan indeks dominasi parasit pada udang vannamei serta hubungannya dengan umur pemeliharaan (DOC) dan kondisi kualitas air. Penelitian dilaksanakan pada April–Agustus 2025 di enam lokasi tambak yang mewakili empat kabupaten (Aceh Besar, Aceh Jaya, Aceh Barat, dan Nagan Raya). Sebanyak 630 ekor udang diperiksa menggunakan metode pengamatan mikroskopis pada organ eksternal dan internal, dan data dianalisis menggunakan ANOVA dua arah. Hasil penelitian menunjukkan bahwa 57,14% sampel terinfestasi ektoparasit. Tiga spesies protozoa epibion teridentifikasi, yaitu Zoothamnium sp. (1.412 individu), Epistylis sp. (1.114 individu), dan Vorticella sp. (410 individu). Prevalensi tertinggi dijumpai pada tambak intensif Aceh Barat (74,29%), diikuti Nagan Raya (63,81%), Aceh Besar intensif (60,95%), Aceh Jaya intensif (59,05%), Aceh Jaya semi intensif (44,76%), dan terendah Aceh Besar semi intensif (40,00%). Intensitas serangan tertinggi terdapat pada Aceh Barat intensif (9 ind/ekor), sedangkan tambak semi intensif menunjukkan intensitas lebih rendah (7 ind/ekor). Organ yang paling banyak terinfestasi adalah kaki renang (876 individu), insang (672), dan kaki jalan (614). Nilai indeks dominasi tertinggi tercatat pada tambak intensif Aceh Besar (D = 0,44). Secara temporal, jumlah parasit meningkat seiring bertambahnya umur pemeliharaan dari DOC 30 (1,24 ± 2,87) menjadi DOC 60 (1,59 ± 3,48) dan DOC 90 (1,83 ± 3,79). Analisis ANOVA menunjukkan bahwa lokasi (p = 0,000) dan DOC (p = 0,009) berpengaruh signifikan terhadap jumlah parasit, sedangkan interaksi keduanya tidak signifikan (p = 0,999). Kisaran kualitas air pada lokasi penelitian meliputi suhu 30–31,4°C, pH 7,37–7,79, DO 4,27–6,06 mg/L, salinitas 15–27‰, NH₃ 0,022–0,775 mg/L, NO₂ 0,019–0,158 mg/L, dan NO₃ 6,2–19,8 mg/L, di mana tingginya amonia dan nitrit pada tambak intensif berasosiasi dengan tingginya infestasi ektoparasit. Disimpulkan bahwa tingkat serangan parasit pada udang vannamei sangat dipengaruhi oleh sistem budidaya, kualitas air, dan umur pemeliharaan. Tambak intensif menunjukkan prevalensi, intensitas, dan dominansi ektoparasit yang lebih tinggi dibandingkan tambak semi intensif. Zoothamnium sp. merupakan spesies paling dominan pada seluruh lokasi penelitian.
Kata Kunci : Udang, Ektoparasit, Prevalensi, Intensitas, Indeks, Dominasi

Ectoparasite infestation in vannamei shrimp (Litopenaeus vannamei) has been widely reported, but quantitative information on differences in infestation levels between intensive and semi-intensive farming systems on the west coast of Aceh is still limited. This study aims to determine the prevalence, intensity, and dominance index of parasites in vannamei shrimp and their relationship with age at harvest (DOC) and water quality conditions. The study was conducted from April to August 2025 at six pond locations representing four districts (Aceh Besar, Aceh Jaya, Aceh Barat, and Nagan Raya). A total of 630 shrimp were examined using microscopic observation of external and internal organs, and the data were analyzed using two-way ANOVA. The results showed that 57.14% of the samples were infested with ectoparasites. Three species of epibiont protozoa were identified, namely Zoothamnium sp. (1,412 individuals), Epistylis sp. (1,114 individuals), and Vorticella sp. (410 individuals). The highest prevalence was found in intensive ponds in West Aceh (74.29%), followed by Nagan Raya (63.81%), intensive Aceh Besar (60.95%), intensive Aceh Jaya (59.05%), semi-intensive Aceh Jaya (44.76%), and the lowest in semi-intensive Aceh Besar (40.00%). The highest attack intensity was found in intensive ponds in West Aceh (9 individuals/fish), while semi-intensive ponds showed lower intensity (7 individuals/fish). The most heavily infested organs were the swimming legs (876 individuals), gills (672), and walking legs (614). The highest dominance index value was recorded in the intensive ponds of Aceh Besar (D = 0.44). Temporally, the number of parasites increased with age from DOC 30 (1,24 ± 2,87) to DOC 60 (1,59 ± 3,48) and DOC 90 (1,83 ± 3,79). ANOVA analysis showed that location (p = 0.000) and DOC (p = 0.009) had a significant effect on the number of parasites, while the interaction between the two was not significant (p = 0.999). The range of water quality at the study site included a temperature of 30–31.4°C, pH 7.37–7.79, DO 4.27–6.06 mg/L, salinity 15–27‰, NH₃ 0.022–0.775 mg/L, NO₂ 0.019–0.158 mg/L, and NO₃ 6.2–19.8 mg/L, where high ammonia and nitrite levels in intensive ponds were associated with high ectoparasite infestation. It was concluded that the level of parasite attack on vannamei shrimp is greatly influenced by the farming system, water quality, and age of cultivation. Intensive ponds showed higher prevalence, intensity, and dominance of ectoparasites compared to semi-intensive ponds. Zoothamnium sp. was the most dominant species at all study sites. Keywords : Shrimp, Ectoparasites, Prevalence, Intensity, Index, Dominance