Host Abundance, Sea-Grass Cover, and Temperature Predict Infection Rates of Parasitic Isopods (Bopyridae) on Caridean Shrimp

Nymphal Rhipicephalus appendiculatus (Trans-Mara) were fed on a steer infected with a Theileria parva parva (Kilae 1) stock isolated from an indigenous steer in the Trans-Mara Division, Kenya, which had a high piroplasm parasitaemia. A total of 5000 engorged nymphs which had dropped on one day were enclosed in elongated nylon bolting silk tubes in groups of 200–300 and were transported immediately to the Trans-Mara where they were suspended vertically in the grass cover with one end touching the ground. Over 98% of the nymphs moulted into adult ticks and 50% moult occurred by day 28 after exposure. The ticks showed over 80% survival up to 308 days post-exposure but thereafter showed a marked mortality so that only 22·5 % of the ticks were alive after 439 days. Theileria parasites were detected in the salivary glands by day 35 post-exposure and infection rates and levels increased markedly between 180 and 235 days post-exposure. Thereafter, the infection rates and levels generally decreased. Groups of ticks were triturated and the resultant supernatant fluid inoculated into pairs of susceptible cattle, and these proved infective from day 44 to 145 after exposure. Three subsequent attempts to induce infections with supernatant fluid were unsuccessful. From 294 days after exposure, groups of 50 ticks were applied to cattle and caused lethal T. p. parva infections up to 439 days post-exposure. Climatic observations showed a relatively even monthly rainfall as well as mean maximum and minimum monthly temperatures. Clean nymphal R. appendiculatus were applied to a steer infected by adult ticks exposed for 405 days and the resultant adults were incubated at 37 °C for 6 days. Supernatant fluid produced from these ticks caused a lethal T. parva infection in a susceptible steer.

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DIVERSITY OF BRITTLE STARS (OPHIUROIDEA) IN TALISE WATERS, NORTH SULAWESI

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.29244/jitkt.v9i2.19303 ◽

2018 ◽

Vol 9 (2) ◽

pp. 709-716 ◽

Cited By ~ 1

Author(s):

Doni Nurdiansah ◽

. Supono

Keyword(s):

Reef Flat ◽

Coastal Areas ◽

Brittle Star ◽

Grass Cover ◽

Associated Fauna ◽

Brittle Stars ◽

Adjacent Water ◽

North Sulawesi ◽

Sea Grass ◽

Ecological Feature

Talise waters, located in North Sulawesi, is one of many coastal areas in Indonesia with sea grass cover extending along the reef flat. This ecological feature is beneficial for living habitat of associated fauna, including brittle stars. Brittle stars are group of Echinodermata reported to be abundantly found in sea grass ecosystem. However, the diversity of this fauna is less reported except as part of echinoderm studies. This research aims to investigate the diversity of brittle stars in Talise waters. Data were collected in July 2009 applying quadrant transect method. In total of 650 individuals belonging to 4 families (Ophiotrichidae, Ophiodermatidae, Ophiocomidae and Ophiuridae) and 10 species were recorded during this study. The diversity (H’=1.58), richness (D=1.69) and Evennes Index (J=0.89) was relatively higher compared to adjacent water in North Sulawesi such as Wori (H =1.64, D =1.38, J=0.85), Kema (H =1.3, D =0.38, J=0.36) but lower than East Likupang waters (H =1.95, D =2.42, J=0.97). Keywords: brittle star, diversity, richness, evennes, Talise waters

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Implications of Seagrass Ecosystem Degradation on Marine Resources and People’s Livelihood: A Case Study from Komave Village, Fiji

Asian Journal of Fisheries and Aquatic Research ◽

10.9734/ajfar/2018/v2i330011 ◽

2019 ◽

pp. 1-13

Author(s):

Lionel Joseph ◽

Priyatma Singh ◽

Ajay Ashneel Singh ◽

Kushaal Raj ◽

Anish Maharaj

Keyword(s):

Marine Ecosystems ◽

Anthropogenic Activity ◽

Nitrate Content ◽

Seagrass Habitat ◽

Grass Cover ◽

Coastal Zones ◽

Seagrass Ecosystem ◽

Sea Grass ◽

Seagrass Cover ◽

The Impact

Tropical coastal zones have rich marine ecosystems; however, they have been enduring severe environmental hazards, particularly from anthropogenic activity and the effects of climate change. Seagrass ecosystem is one of the most productive yet undervalued marine ecosystems. The residents of Komave village, located on the mainland of Fiji have witnessed marked losses in seagrass cover over the last decade. Several of the village men in Komave are unemployed and rely on the coastal resources through fishing, livestock and agricultural farming for their socioeconomic livelihood. This research explores the impact of loss of seagrass cover on the villagers’ livelihood. This paper highlights the observations and experiences of the Komave villagers, in light of the interviews and discussions carried out at the community. A random sampling method was also used over a period of two years (March, 2015 – April, 2017) to monitor the seagrass habitat. The possible anthropogenic and natural factors contributing to the loss of Seagrass were gotten from the interviews and sampling physical environment. The nitrate content analysed from the random samples, reported values from 190 mg/L to a maximum value of 362.8 mg/L. It was also revealed that the areas where nitrate concentrations were greater than 300 mg/L, there was 0% sea grass cover in total, which confirms that if high levels of nitrates are present, sea grass cover is highly impacted. This paper concludes by providing recommendations for managing seagrass to enhance fisheries productivity in this tropical coastal community.

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