Dracunculoid and Anguillicoloid Nematodes Parasitic in Vertebrates (Ukázka, strana 99)

systematic review of dracunculoid and anguillicoloid nematodes

Genus Syngnathinema moravec, spangenberg et frasca, 2001

97

body filiform, head end rounded, caudal end conical. cuticle smooth. oral aperture large, oval, with narrow peribuccal ring surrounded by cephalic papillae in 2 circles: 4 external, 6 internal papillae; lateral amphids large, circular. buccal capsule absent. oesophagus divided into anterior, short and narrow muscular portion and posterior, long and wide glandular portion.

Anterior end of esophagus somewhat bulbously inflated, mouth cavity spacious. nerve ring encircling muscular esophagus at its anterior half, excretory pore slightly posterior to level of nerve ring. female with functional anus; tail conical, sharply pointed. monodelphic. major part of female body filled with uterus containing larvae; uterus may extend anteriorly to level of glandular esophagus. Vulva situated a short distance posterior to esophagus; ovary straight and long, near end of intestine. male unknown. intravascular parasites of marine fishes. type- and the only species: S. californiense moravec, Spangenberg et frasca, 2001.

Syngnathinema californiense moravec, spangenberg et frasca, 2001

fig. 14

Description: f e m a l e : body filiform, long, white. cuticle smooth. cephalic end rounded. oral aperture oval, large, with narrow peribuccal ring, surrounded by 6 small papillae of inner circle, 4 larger submedian papillae of outer circle; lateral amphids large, circular, between both circles of cephalic papillae. three oesophageal lobes forming bottom of mouth as flat surfaces. oesophagus composed of narrow short muscular portion and wide long glandular portion; former somewhat distended at anterior end, its short posterior-most part submerged into anterior end of glandular esophagus; latter almost cylindrical, slightly broadening towards posterior end, provided with small distinct dorsal cell nucleus near its end. intestine straight, lightcoloured, gradually narrowing towards posterior end. nerve ring encircling muscular oesophagus somewhat anterior to its middle. excretory pore short distance posterior to level of nerve ring. deirids not found. Rectum short hyaline tube. Small unicellular rectal glands present. Anus functional. tail conical, sharply pointed. body length of gravid and subgravid specimens 28.084–53.706 mm, maximum width 0.190–0.367. two females containing larvae in anterior part of uterus 50.973 mm and 53.706 mm long and 0.299 mm and 0.367 mm wide, respectively; all remaining specimens (with only eggs in uterus) smaller. length of entire oesophagus 1.972–2.353 mm, representing 4–5 % of body length. muscular oesophagus (without its submerged part) 0.422–0.639 mm long and 0.030–0.048 mm wide, its broader anterior end 0.042–0.057 mm wide; length of its submerged part 0.095–0.109 mm;

Ukázka elektronické knihy, UID: KOS182533

98

systematic review of dracunculoid and anguillicoloid nematodes

UkĂĄzka elektronickĂŠ knihy, UID: KOS182533

systematic review of dracunculoid and anguillicoloid nematodes

99

glandular oesophagus 1.450–1.768 mm long and 0.109–0.163 mm wide. length ratio of muscular and glandular portions of esophagus 1 : 2.55–3.44. nerve ring and excretory pore 0.245–0.313 mm and 0.286–0.394 mm from anterior extremity, respectively. Vulva situated somewhat posterior to oesophagus, 1.945–3.169 mm from anterior extremity, 0.109–1.401 mm from end of oesophagus; in one small specimen (body length 38.216 mm) slightly anterior (0.041 mm) to esophageal end. Vagina narrow, muscular near distal end, directed posteriorly from vulva. Vulvar lips somewhat elevated in largest specimens. monodelphic. in specimens with larvae, anterior part of uterus extending anteriorly up to level of vulva or even to border of first third of glandular oesophagus; uterus in posterior direction containing progressively fully developed larvae, oval larvated eggs, and immature eggs. oviduct short, forming coils. ovary straight, long and wide, ending 0.313–1.292 mm anterior to anal aperture. tail 0.261–0.354 mm long. first-stage larvae from uterus 0.609–0.672 mm long and 0.030–0.033 mm wide; oesophagus 0.177–0.195 mm long (29–30% of body length) and 0.021–0.027 mm wide; tail 0.114–0.144 mm long (19–21% of body length); nerve ring 0.057–0.078 mm from anterior extremity; rectum 0.042–0.060 mm long.

Host: bay pipefish, Syngnathus leptorhynchus (Syngnathidae, Syngnathiformes). site of infection: circulatory system (sinus venosus, atrium, renal and hepatic veins).

Distribution: Reported from an aquarium in San francisco, california, uSA (fishes collected from San francisco bay and Vancouver, british columbia, canada) (moravec, Spangenberg and frasca 2001). biology: the life cycle is unknown. moravec, Spangenberg and frasca (2001) found this parasite in 63% of S. leptorhynchus examined from california, with the intensity 2–5 specimens per fish. family Dracunculidae stiles, 1907

body long and thin, gravid females considerably longer than males. cephalic end rounded, often with cuticularized shield. lips or pseudolabia absent. oesophagus divided into short anterior muscular and very long posterior glandular portions; glandular oesophagus with conspicuous large swelling at anterior end. nerve ring encircling glandular oesophagus just fig. 14. Syngnathinema californiense moravec, Spangenberg et frasca, 2001, female. A – anterior end, lateral view; b – anterior part of body; c – cephalic end, apical view; d – anterior part of body of specimen with uterus extending to anterior half of glandular oesophagus; e – posterior end; f – larva from uterus; G – tail. Scale bars: A, f, G – 0.1 mm; b – 0.2 mm ; c – 0.02 mm; d, e – 0.5 mm. (After moravec, Spangenberg and frasca 2001.)

Ukázka elektronické knihy, UID: KOS182533