Mobashir A. Solangi

Biology and pathogenesis of the coccidium Eimeria funduli infecting killifishes.

Epizootics of Eimeria funduli involved estuarine killifishes (Fundulus grandis, F. pulvereus, F. similis, and F. heteroclitus) in Mississippi, Alabama, and Virginia. All of more than 500 specimens examined of F. grandis from Mississippi during 1977 though 1979 had infections, regardless of age, sex, or season collected. Oocysts occurred primarily in the liver and pancreas, replacing up to 85% of both those organs. Infrequent sites of infection were fatty tissue of the body cavity, ovary, intestine, and caudal peduncle. Living fish did not discharge oocysts. Eimeria funduli is the first known eimerian to require a second host. To complete the life cycle, an infective stage in the grass shrimp Palaemonetes pugio had to be eaten. In 6-mo-old killifish reared in the laboratory at 24 C, young schizonts were first observed in hepatic and pancreatic cells 5 days postfeeding, followed by first generation merzoites by day 10, differentiation of sexual stages during days 15 to 20, fertilization between days 19 and 26, sporoblasts from days 25 to 30, and sporozoites about day 60. Unique sporopodia developed on sporocysts by day 35 when still unsporulated. Temperatures of 7 to 10 C irreversibly halted schizogony. Both schizogony and sporogony progressed slower as age of host increased. When infective shrimp in doses ranging from 1 to 10% of a fishs body weight were eaten, the level of intensity of resulting infections did not differ significantly. Pathogenesis followed a specific sequence, with the host response apparently unable to contend with extensive infections as seen typically in nature and in our experiments. Premunition was indicated. When administered Monensin orally, infected fish exhibited a reduction in oocysts by 50 to 70% within 20 days as compared with untreated fish. Furthermore, infected killifish exclusively on a diet of TetraMin for 3 mo completely lost their infections.

A new and unusual eimerian (protozoa: Eimeriidae) from the liver of the Gulf killifish, Fundulus grandis.

Oocysts and sporocysts of Eimeria funduli sp. n. are described from the Gulf killifish, Fundulus grandis, on the basis of light microscopy, transmission and scanning electron microscopy, and location in the liver of infected hosts. The spherical sporu!ated oocysts of E. funduli isolated from liver tissue measure 20–31(25) ıtm across with ovoid sporocysts 9–11 × 5–7 (10 × 6) ıtm. A micropyle, polar granule, and oocyst residuum are absent, but sporocysts have Stieda and substieda bodies, a few residual granules, and 10–25 (15) unique projecting structures with expanded distal portions that we term “sporopodia”. Sporopodia 1–3 (2) ı high support a transparent membrane that completely surrounds the sporocyst. Sporozoites have one large posterior refracti!e body. U!trastructural!y, the oocyst wall consists of two thin layers of granular material: an electron-dense outer layer with a rough external surface and an electron-lucent inner one of approximately equal thickness. One or two unit membranes line the inner surface of the inner layer. Each layer is 40–60(55) nm thick. The sporocyst wall, 78–130 (110) nm thick, consists of an e!ectron-lucent material with the outer surface being more electron dense and giving rise to osmiophilic sporopodia; closely associated with these and the outer surface are one or two unit membranes. A thin osmiophi!ic layer of fine granular material lines the inner surface.

Vertebral Osteomyelitis and Suspected Diskospondylitis in an Atlantic Bottlenose Dolphin (Tursiops truncates)

A 21-yr-old male Atlantic bottle-nose dolphin (Tursiops truncatus) was performing at an aquatic park when it developed a soft tissue swelling anterior to the flukes. Subsequent radiographic evaluation revealed the animal to have vertebral osteomyelitis and suspected diskospondylitis. The case was successfully managed with long-term antibiotic therapy.

Two New Species of Symbiotic Ciliates from the Respiratory Tract of Cetaceans with Establishment of the New Genus Planilamina n. gen. (Dysteriida, Kyaroikeidae)

ABSTRACT. Examination of mucus discharged from the blowhole of Atlantic bottlenose dolphin (Tursiops truncatus) at Marine Life Oceanarium, Gulfport, Mississippi, and false killer whale (Pseudorca crassidens) and Atlantic bottlenose dolphin at SeaWorld Orlando, Orlando, Florida, using live observations and protargol impregnation revealed mixed infections of Kyaroikeus cetarius and two new species. Planilamina n. gen. is characterized by a C‐shaped argentophilic band located along the laterally flattened margin of cell and extending from the cell apex to subposterior cone‐shaped podite; a deep oral cavity containing one short preoral kinety, two circumoral kineties, seven to 13 infundibular kineties, and a cytostome; a broadly funnel‐shaped cytopharynx reinforced by argentophilic fibers but without nematodesmata; closely packed postoral kinetofragments set in a pocket located anterior left of the podite; and somatic kineties as a right field closely situated at the right surface and a left field bordering the anterior left margin of the oral cavity. The type species for the genus, Planilamina ovata n. sp., is distinguished from its sister species Planilamina magna n. sp. by the following characteristics: body size (28–65 × 20–43 μm vs. 57–90 × 40–63 μm), number of right field kineties (38–55 vs. 79–99), and position of the anterior end of the leftmost kinety in the right somatic field (anterior one‐third vs. mid‐body). The morphogenesis of Planilamina ovata is similar to that of K. cetarius. The diagnosis of Kyaroikeidae is emended to accommodate the new genus.