Mazocraeoides prashadi Chauhan, 1950

Sailaja, Bade, Shameem, Ummey & Madhavi, Rokkam, 2019, Four species of Mazocraeoides Price, 1936 (Monogenea: Mazocraeidae), including two new species from clupeiform fishes off Visakhapatnam coast, Bay of Bengal, Zootaxa 4608 (2), pp. 233-246 : 238

Mazocraeoides prashadi Chauhan, 1950

( Figs.10–13 )

Host: Sardinella longiceps (Valenciennes) (Clupeidae) .

Locality: Visakhapatnam coast, Bay of Bengal.

Site in host: Gills.

Specimens deposited: Zoological Survey of India, Kolkata, India. Voucher specimen 10436/1.

Prevalence and mean intensity: 23.72% and 1.5 worms per infected fish.

Redescription: (Measurements based on 4 specimens) Body lanceolate, broad posteriorly, narrow anteriorly, tegument thick, opaque. Body size 1108 (976–1184) long, 304 (272–384) wide. Clamps four pairs, embedded in posterior half of body, with first pair at distance of 452 (416–528) from anterior end. All clamps of equal size, 20x 21 long. Clamp skeleton with five sclerites, SAA, SAS, SMB, SMS, SL. Oral suckers oval, 25 (20–28) x 18 (16–20) in size. Pharynx elliptical, compact, muscular situated behind two anterior suckers. Esophagus long. Ceca broad with lateral branches extend to near posterior end of body. Lappet not differentiated from body proper. Posterior region of body provided with two pairs of anchors and one pair of hooks. Outer pair of anchors long, 10 in length, with straight shaft, prominent spur and curved blade. Inner pair of anchors smaller, 4.5 (4–5) long, hooks very small, visible only in few forms.

Genital pore median, at distance of 170 (156–184) from anterior end. Testis single, oval, situated in intercecal region in posterior third of body. Genital complex prominent, sucker- like with thick muscular wall composed of concentric rings of muscles, occupies entire width of neck region, 39 (32–44) long x 34 (28–40) wide, armed with five pairs of triangular median hooks, arranged in two vertical rows with tips overlapping one another and one pair of comparatively long lateral hooks with broad base, inserted on either side of median group of hooks.

Ovary rounded, pretesticular, 220 (200–240) x 140. Eggs large, elliptical, 122 x 66 in size.

Genito-intestinal canal, vagina not visible. Vitelline follicles numerous extend from intestinal bifurcation to posterior end of body. Vitelline reservoir Y-shaped, prominent.

Remarks: The species is characterized by the short oval and opaque body with small clamps arranged in the posterior half of the body. The most distinguishing features of the species are the large, prominent genital complex occupying the entire width of the body situated at the level of the intestinal bifurcation and the genital armature consisting of one pair of long lateral hooks with a broad base and five pairs of sickle-shaped median hooks arranged in two vertical rows with the tips overlapping one another. The present specimens, while fully agreeing with the description of the species given by Chauhan (1950), show a few differences: The body size is larger (972– 1232 x 272–384 vs 440–660 x 140–180), testes and ovary are more posteriorly located in posterior quarter of body rather than in middle third of body. The clamp skeleton has a complicated configuration and a similarity to the detailed structure given by Mamaev (1982). Chauhan’s (1950) description is based on only five specimens and none contained eggs. In the present collection almost 58% of the specimens had eggs that are very large and elliptical. Fur- ther, Chauhan reported only two pairs of anchors at the posterior end, in contrast there are two pairs of anchors and one pair of hooks in the present specimens.

Figures

FIGURES 10–13. Mazocraeoides prashadi. 10. Entire worm, ventral view; 11. Genital atrium (numbers 1–5, median hooks; L, lateral hooks); 12. Clamp; 13.Anchors and hooks. Scale bars: Fig.10, 200µm; Figs.11–12, 10µm; Fig.13, 30µm.