Neopolystoma moleri, PREEZ, LOUIS H. DU & MORRISON, CHRISTA, 2012

PREEZ, LOUIS H. DU & MORRISON, CHRISTA, 2012, Two new polystomes (Monogenea: Polystomatidae) from the eyes of North American freshwater turtles, Zootaxa 3392 (1), pp. 47-59 : 49-50

Neopolystoma moleri n. sp.

( Figs. 2–4 )

Specimens studied: One specimen was used to extract DNA. Morphological description based on five sexually mature worms. Holotype (NMB P335) five paratypes (NMB P336 – P340) deposited in the Parasitic Worm Collection, National Museum, Aliwal Street, Bloemfontein, South Africa.

Type host: Apalone ferox (Schneider, 1783) .

Type locality: Gainesville, Florida. Exact locality unknown. Road killed specimen collected by a member of the public and deposited at the office of the Florida Fish & Wildlife Conservation Commission, 4005 South Main Street, Gainesville FL 32601, USA.

Site: Conjunctival cavity of the eye.

Etymology: This parasite is named after Dr. Paul Moler of the Florida Fish & Wildlife Conservation Commission who provided the specimens.

Description: Based on five egg-producing adults, measurements are given in micrometers. The average measurement is followed by the range given in parentheses. No larval measurements or characters are given, as no oncomiracidia were available.

Adult: General characteristics given of mature, egg-producing parasite ( Figure 2 ). Body elongated, some stretched out, total length 5975 (3249–7944), greatest width 1269 (926–1694), width at vagina 984 (599–1426), haptor length 779 (601–983), haptor width 1027 (784–1426); haptor length to body length ratio 0.16 (0.11–0.21); haptoral suckers 6, mean diameter 280 (225–351). Mouth sub-terminal, ventral. False oral sucker 288 (180–358) wide; pharynx length 309 (243–415), width 331 (258–392). Intestine bifurcate with no diverticula, right caecum 3155 (1692–4126) in length, left caecum 3054 (1894–4101) in length. No anastomoses; caeca do not join posteriorly and do not extend into the haptor.

Testis compact, mid-ventral, medial, and posterior to ovary ( Figure 2 ). Vas deferens contains relatively low amounts of sperm. Genital atrium median, ventral, posterior to intestinal bifurcation: 28 (19–37) in length with 12–13 spines, 9 (8–10) long. Ovary dextral, 15% from anterior end, ovary length 210 (124–312), width 92 (73–138). Short tubular uterus anterior to ovary, one of the five paratypes containing a single egg, length 358, width 168. No intra-uterine development, egg operculate. Vitellarium organised in two broad lateral fields in the first 75% of the body. Genito-intestinal canal prominent, on the same side as ovary, joining intestinal caecum posterior to ovary ( Figure 2 ).

Remarks: Neopolystoma moleri n. sp. differs from other members of the genus by a combination of characters ( Table 1 ). Neopolystoma moleri n. sp. differs from N. elizabethae and N. fentoni : N. moleri n. sp. has an average body length of 5975 and a minimum length of 3249, significantly larger than N. elizabethae and N. fentoni , with body lengths of 3125 and 1985 respectively. Furthermore, N. moleri n. sp. is wider than N. elizabethae and N. fentoni , its minimum width, 926, being larger than the maximum width reported for N. elizabethae and N. fentoni . Neopolystoma moleri n. sp. has a wider haptor and a slightly larger pharynx, while its ovary, with an average length of 210, is slightly smaller than that of N. elizabethae (with an average length of 301), and slightly larger than N. fentoni (with an average length of 103). With an average size of 633 × 548, N. moleri n. sp. has a much larger testis than N. elizabethae (with an average size of 208 × 155), and N. fentoni (with an average size of 225 × 181). Neopolystoma moleri n. sp. can further be distinguished from N. elizabethae and N. fentoni in possessing more genital spines (12–13) compared to eight for N. elizabethae and eight for N. fentoni . Neopolystoma moleri n. sp. has larger eggs (358 × 168) compared to (332 × 146) for N. fentoni and (367 × 122) for N. elizabethae . Finally, N. moleri n. sp. has an average haptor length to body length ratio of 0.16 that distinguishes it further from N. elizabethae (0.28) and N. fentoni (0.29).

Figures

FIGURE 2. Neopolystoma moleri n. sp. Ventral view of holotype; the dotted line indicates the outline of the vitellarium. Abbreviations: gb, genital bulb; gi, genito-intestinal canal; hp, haptor; ic, intestinal caecum; mo, mouth; ov, ovary; ph, pharynx; su, sucker; te, testis; vd, vas deferens; vg, vagina; vi, vitellaria; vt, vitelline duct. Scale bar: 1 mm.

FIGURE 3. Neopolystoma moleri n. sp. A, marginal hooklets 1 from the holotype and paratypes; B, marginal hooklets 2 - 8 from the holotype and paratypes. Scale-bars: 10 µm.

FIGURE 4. Paratypes of Neopolystoma moleri n. sp., demonstrating its ability to stretch lengthwise in order to feed successfully without being dislodged. Scale bar: 1 mm.