Abstract

From October 1974 to February 1979, 48 East Indian Manatees (Trichechus manatus latirostris) were examined for parasites. Most of these animals represented single strandings and originated from both coasts of Florida, primarily during the winter months. The purpose of this study was to qualitatively and quantitatively characterize the parasite fauna of manatees and to assess the impact of parasitism on manatee populations. The fauna was comprised of four types of parasites: Nasal flukes (Opisthotrema cochleotrema) occurred in 50% of the animals with numbers per animal ranging from 2 to 250. Paramphistome flukes (Chiorchis fabaceous) were found in the intestines and cecae of 76% of the manatees with total numbers as high as 24,000 per animal. A third type of fluke (representing several species in the family Microphallidae) was found in the intestines of a number of animals with up to 132,000 being found per manatee. A fourth parasite, the ascaroid nematode Plicatolabia hagenbecki, was present in the stomachs in numbers ranging from 1 to over 1,600 per animal. The potential impact of these parasites on manatees will be discussed.

Notes

A manatee will consume 100 lbs. vegetation per day. 42% of their time is spent feeding.

The last Indian Manatee is in danger. There are 750-1000 manatees in Florida. Mortality is due to boating, flood control dams, habitat alteration and disease.

Parasites

Nasal flukes found attached to the nasal cavity.

Microphallid flukes - seen only under dissecting scope. Collected with a fine mesh screen. Few were found in the Florida West coast manatee.

Ascaroid nematode - 40% of manatees found had this in their stomachs. It can penetrate to the submucosa.

Paramphistome fluke - intestine and caecum.

All four parasites can cause tissue damage and likely contribute to the general debilitation of the animal rendering it more vulnerable to the above mentioned causes of mortality. The life cycles and pathogenesis of these parasites are unknown.