The histopathology of larval anisakid nematode infections in the liver of whiting, Merlangius merlangus (L.), with some observations on blood leucocytes of the fish

Abstract

The cellular response of whiting, Merlangius merlangus (L.), to Contracaecum and Anisakis larvae parasitic in the liver was characterized by the presence of neutrophils, macrophages and proliferating fibroblasts. A capsule formed around the larvae after the removal of all necrotic debris by phagocytic cells. Melanin granules were deposited around the capsule. Four types of blood leucocytes were identified; thrombocytes, lymphocytes, monocytes and neutropbils. Phagocytic activity of the neutrophils and macrophages was suggested by the presence of dark stained bodies within them.

Parasitic infection by larval helminths in Antarctic fishes: pathological changes and impact on the host body condition index

“…In whiting Merlangius merlangus, Contracaecum spp. larvae penetrated liver tissue and became encapsulated within the parenchyma, destroying liver cells, blood vessels and bile ducts with attendant inflammation with heterophils, macrophages and fibroblasts and deposition of melanin around the connective tissue capsule (Elarifi 1982). O'Neill et al (1988) described the chronic inflammatory response in the body cavity of juvenile silverfish to plerocercoids identified as Diphyllobothrium spp.…”

Blood and other possible inflammatory cells in the sparid Acanthopagrus australis (Günther)

“…With regard to the bream monocyte, previous descriptions of teleost monocytes in Romanowsky-stained blood smears are of a large cell with pseudopodia, a pale to dark and often vacuolated basophilic cytoplasm, and a nucleus that is often irregular in outline, rounded or indented and finely reticular (Ellis, 1976;Grizzle & Rogers, 1976;Williams & Warner, 1976;Mahajan & Dheer, 1979;Barber et al, 1981;Elarifi, 1982;Groman, 1982;Yasutake & Wales, 1983). Furthermore, the ultrastructural features of the monocyte of the bream (large Golgi complex with numerous vesicles, few small granules, pseudopodia, rER and vacuoles) resemble those given for the monocytes of other teleosts (Ferguson, 1976;Kreutzmann, 1977;Bielek, 1980b;Hawkins et al, 1981;Cenini, 1984).…”

“…Furthermore, the ultrastructural features of the monocyte of the bream (large Golgi complex with numerous vesicles, few small granules, pseudopodia, rER and vacuoles) resemble those given for the monocytes of other teleosts (Ferguson, 1976;Kreutzmann, 1977;Bielek, 1980b;Hawkins et al, 1981;Cenini, 1984). LYMPHOCYTE Although large and small lymphocytes have been described in teleosts by a number of authors (e.g., Klontz, 1972;Hines & Spira, 1973;Christensen et al, 1978;Lewis et af., 1979;Mahajan & Dheer, 1979), some authors (Williams & Warner, 1976;Elarifi, 1982), as well as myself, have only recognized one type of lymphocyte with a large size-range. Ellis (1977) points out that the distinction between large and small lymphocytes may be arbitrary as they probably represent different stages of the same cell type, but immunological evidence for two types of lymphocytes in the channel catfish, Ictalurus punctatus, has been provided by Lewis et al (1979), and an extensive discussion given by Ellis (1982).…”

Stromal Cells, Macrophages and Lymphoid Cells in the Head-kidney of Sea Bass (Dicentrarchus labrax L.). An Ultrastructural Study.

“…These may be two different functional stages of the same cell type (ELLIS, 1977), or two separate cell populations with different functional properties (PARROT and DESOUSA, 1971). Nevertheless, large and small lymphocytes have not been distinguished in some teleost species, with only a large lymphocyte type being recorded (WILLIAMS and WARNER, 1976;ELARIFI, 1982;ROUBAL, 1986). In the sea bass head-kidney we have identified both small and large lymphocytes according to the results of a light microscopical study previously carried out (ROMESTAND and TRILLES, 1984).…”