Dichelyne (Dichelyne) bonacii n. sp. (Nematoda: Cucullanidae) from the grey snapper Lutjanus griseus and the black grouper Mycteroperca bonaci off the coast of Yucatán, Mexico

Abstract

A new cucullanid, Dichelyne bonacii n. sp., is described from the intestine of the grey snapper Lutjanus griseus and the stomach of the black grouper Mycteroperca bonaci off the coast of Yucatán. The absence of a ventral precloacal sucker and the presence of 11 pairs of caudal papillae in males allocate it to the subgenus Dichelyne. It differs from its congeners in body dimensions and by having two almost equal spicules (left 712-950 and right 722-945microm), two intestinal caeca and in the position of the deirids and excretory pore. Apparently, L. griseus acts as definitive host of this species, whereas M. bonaci may be considered as a postcyclic host. This new species represents the first record of a nematode of the subgenus Dichelyne in marine fishes of Mexico.

Cucullanid nematodes (Nematoda: Cucullanidae) from deep-sea marine fishes off New Caledonia, including Dichelyne etelidis n. sp.

“…Such papillae of the internal circle have not been observed in many other congeneric species (e.g. González-Solís et al, 2002;Alarcos et al, 2006). Although their presence in D. etelidis cannot be excluded, they are not visible in available SEM micrographs.…”

“…Apparently, these structures are identical with those described by Jägerskiöld (1902Jägerskiöld ( , 1909 as asymmetrical ''Mittelkörperpapillen'' in D. fossor; considerably asymmetrical postdeirids (considered to be the first, lateral pair of pre-anal genital papillae) have been reported in the male of the same species by Moravec (1974). Dorsolateral postdeirids, asymmetrically located anterior to the genital papillae in males and in the region of the vulva in females, have been reported for many species of Dichelyne (see Petter, 1995;González-Solís et al 2002;Timi & Sardella, 2002;Alarcos et al, 2006) and Cucullanus (see Moravec et al, 1993;Crites & Overstreet, 1997;Lanfranchi et al, 2004). Sometimes it is not easy to find postdeirids in cucullanids and this may be the reason why they tend not to be reported in the descriptions of these nematodes and were not found in D. etelidis females.…”

“…At present, the subgenus Dichelyne (Dichelyne) includes 18 nominal species parasitic in freshwater, brackishwater and marine fishes (Moravec et al, 1999(Moravec et al, , 2001González-Solís et al, 2002). Petter (1974a) also listed Dichelyne (D.) exiguus (Yamaguti, 1954), D. (D.) lutjani (Schmidt & Kuntz, 1969) and D. (D.) fastigatus Chandler, 1935 in this subgenus; however, the first two species should be considered members of Cucullanus Müller, 1777 (see Moravec et al, 1999), whereas the third species belongs to a different subgenus of Dichelyne, Cucullanellus Törnquist, 1931, according to Moravec et al (2011).…”

“…Of the 18 known Dichelyne (Dichelyne) species, only the following nine are parasites of marine or brackishwater fishes: D. alatae De & Maity, 1995, D. bonacii González-Solís, Argáez-García & Guillén-Hernández, 2002, D. diminutus (Rasheed, 1968, D. indentatus (Rasheed, 1968), D. japonicus Moravec, Nagasawa & Ogawa, 2001, D. longispiculatus Wang & Ling, 1975, D. pomadasysi Vassiliadès & Petter, 1981, D. rasheedae Petter, 1974and D. spinicaudatus Petter, 1974(see Rasheed, 1968Petter, 1974b;Wang & Ling, 1975;Vassiliadès & Petter, 1981;De & Maity, 1995;Gibbons & Saayman, 1996;Timi et al, 1997;Moravec et al, 2001;González-Solís et al, 2002). Their hosts mostly belong to the perciform families Carangidae, Centropomidae, Haemulidae, Lutjanidae, Polynemidae, Sciaenidae, Serranidae and Sillaginidae; one species, D. longispiculatus, was reported from a fish of the clupeiform family Clupeidae in addition to a sciaenid host.…”

New data on the morphology of Dichelyne hartwichi (Nematoda, Cucullanidae), a parasite of freshwater tetraodontid fishes (Tetraodon spp.) in Thailand

“…In most other species of Dichelyne, the papillae of the last subventral preanal pair resemble in size those of the foregoing pairs or are only slightly smaller, as observed, for example, in D. (D.) bonacii González-Solís, Argáez-García et Guillén-Hernández, 2002(see González-Solís et al 2002.…”