Scanning electron microscopic study of Prosorhynchoides arcuatus (Linton, 1990) (Bucephalidae: Digenea)

Abstract

Prosorhynchoides arcuatus (Linton, 1900) from the intestine of Pomatomus saltator (L.) from the Atlantic coast of the State of Rio de Janeiro is studied by scanning electron microscopy, with detailed description of tegumental spines. Comments on the synonymy of this species with Bucephalopsis callicotyle Kohn, 1962 are made. The tegument of adult P. arcuatus presents scale like and serrated spines and uniciliated sensory papillae, distributed over the body surface and is compared with other digenetic trematodes.

Topography and ultrastructure of the tegument of Aphallus tubarium (Rodolphi, 1819) Poche, 1926 (Digenea: Cryptogonimidae), intestinal parasite of the common Dentex dentex (Linnaeus 1758) from Valinco Gulf

“…Sensory receptors are common and varied among digeneans. They have been observed singly or grouped, bearing short or long cilia or devoid of cilia (Cohen et al, 1995;Han et al, 2003;Ostrowski de Nũnez et al, 2011). Our results highlighted 2 types of sensory structures already identified in other Cryptogonimidae species such as Parspina argentinensis Szidat 1954 or Metadena phoceae Bartoli and Gibson 2001.…”

“…The ultrastructural configuration of type 1 receptor is similar to those observed in some digeneans, even though small modifications appear from other species. Some digenean species such as Diplostomum pseudospathaecum Niewiadomska, 1984 or Prosorhynchoides arcuatus (Linton, 1900) Bray, 1984 posses a conical dense structure and rootlets on basal body of cilium not observed on A. tubarium (Cohen et al, 1995;Czubaj and Niewiadomska, 1996). Our study revealed also a difference in mean cilia lengths between A. tubarium and other species (Ostrowski de Nũnez et al, 2011).…”

“…Bucephalus Baer 1826, Himasthla Dietz 1909, Pygidiopsis Koie, 1990 or Prosorhynchus Odhner 1905 (Køie, 1992;Cohen et al, 1995;João Santos and Gibson, 2002;Han et al, 2003). Tegument morphology is seldom used for differentiating between genera (Miller and Cribb, 2008), but it may be useful for separating species.…”

“…The number of digitations differs from other digenean species according parts of body. Cohen et al (1995) described spines on the anterior part tegument of P. arcuatus, with up to 30 digitations. Pandey and Tewari (1984) found spines with 3 to 25 digitations in the anterior part of Bucephalopsis karvei and a posterior part of body unspined, whereas A. tubarium posses the highest number of digitations on the posterior part (N = 36.89).…”

“…The mechanism of attachment is probably mediated by tactile sensory papillae (type 2 receptors) abundant around the oral sucker of A. tubarium. These papillae probably act as rheoreceptors/tangoreceptors involved in mechanisms of feeding and attachment, detecting contact with host-tissue and manipulating the adhesive pressure of the sucker-like organ (Ramasamy et al, 1987;Cohen et al, 1995;Abdul-Salam and Sreelatha, 2000). On the other hand, type 1 receptor could possibly be chemoreceptors used in recognition of host chemical stimuli serving to orient the body during feeding and mating (Whittington et al, 2000;Buchmann and Lindenstrøm, 2002).…”