The first description of eggs in the male reproductive system of Physaloptera bispiculata (Nematoda: Spiruroidaea)

Abstract

Physaloptera bispiculata (Nematoda: Spiruroidaea) is a parasite of Nectomys squamipes (Rodentia: Cricetidae), a water rat that only occurs in Brazil. Naturally infected rodents were captured in the municipality of Rio Bonito, Rio de Janeiro, Brazil. Adult P. bispiculata worms were collected, prepared and analysed by light and scanning electron microscopy. Under scanning electron microscopy, several eggs were seen glued by cement to the cloacal aperture. Light microscopy revealed that some male worms had an uncountable number of embryonated eggs in the ejaculatory duct, cloaca and also in the posterior portion of the intestine. The probable explanation is that the eggs developing in the female uterus are pumped by the female or sucked by the male to the cloacal opening and from this point to the intestine and ejaculatory duct. The male probably does not have the ability to expel the eggs and for this reason a large number were found in these organs. On the other hand, this could be an important adaptation for the parasite, i.e. male worms expelled by the host can carry a large number of eggs and spread them to intermediate hosts when ingested by these hosts. As far as we know this is the first record of a physalopterid nematode harbouring eggs in the cloacal region, ejaculatory duct or intestine.

Clarifying prehistoric parasitism from a complementary morphological and molecular approach

“…It is also known to infect baboons and chimpanzees as well as other Simian primates. Physaloptera caucasica and Physaloptera mordens have both been identified in humans; today they are considered synonymous (Irwin-Smith, 1921; Hahn, et al, 2003; Hira, 1978; Lleras and Pan, 1955; Mbora and McPeek, 2009; Morgan, 1945; Murray, et al, 2000; Mutani, et al, 2003; Oliveira-Menezes, et al, 2011; Ortlepp, 1922, 1926; Weyher, et al, 2006). An infection has been documented involving an 11 month old infant in 1977 which require surgical intervention to cure.…”

Scanning electron microscopy observations of the hedgehog stomach worm, Physaloptera clausa (Spirurida: Physalopteridae)

“…In H. longissimum , the vulva is situated at 39-66% of body length from the apical extremity, while it is located 1.14-1.36 mm from the posterior end of the body of P. obtusus [24,26]. The presence of eggs in the male reproductive system of P. bispiculata was described by Oliveira-Menezes et al in 2010 [42]. To the best of our knowledge, this is the first report of a male physalopterid nematode harbouring eggs in the cloacal region, ejaculatory duct or intestine.…”

“…To the best of our knowledge, this is the first report of a male physalopterid nematode harbouring eggs in the cloacal region, ejaculatory duct or intestine. Several eggs were observed glued by cement to the cloacal aperture, using scanning electron microscopy [42]. Light microscopy revealed that some males had an uncountable number of embryonated eggs in the ejaculatory duct, cloaca and also in the posterior part of the intestine [42].…”

“…Several eggs were observed glued by cement to the cloacal aperture, using scanning electron microscopy [42]. Light microscopy revealed that some males had an uncountable number of embryonated eggs in the ejaculatory duct, cloaca and also in the posterior part of the intestine [42]. The probable explanation is that the eggs developing in the female uterus are pumped by the female or sucked by the male to the cloacal opening and from this point to the intestine and ejaculatory duct.…”

“…The male worm may be unable to expel the eggs and a large number were found in these organs. In addition, this could be an important adaptation for the parasite, for example the males expelled by the host can carry a large number of eggs and spread them to intermediate hosts when ingested by these hosts [42]. The vulva of T. turgida is located in the anterior end of the body, and like in P. clausa , the conical tail bore an anal opening, with phasmids located posteriorly [23].…”