Mazocraeoides fusiformes, Sailaja & Shameem & Madhavi, 2019

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 : 236-238

Mazocraeoides fusiformes n. sp.

( Figs. 5–9 )

Type -Host: Stolephorus indicus (Van Hasselt) (Engraulidae)

Type -locality: Visakhapatnam coast, Bay of Bengal .

Site in host: Gills.

Material deposited: Zoological Survey of India, Kolkata, India. Holotype W10439/1, paratype W10440/ 1. Natural History Museum, London. Paratype NHMUK 2019.3 .15.1.

Prevalence and mean intensity: 40.32% and 3.36 worms per infected fish.

ZooBank registration: The Life Science Identifier (LSID) for Mazocraeoides fusiformes n. sp. is urn:lsid:zoobank.org:act:8E9B4452-D313-4970-AA6C-51D3E9C94964

Etymology: The specific name indicates the fusiform shape of the body.

Description: (Measurements based on 6 specimens) Body elongate, broad posteriorly, narrow anteriorly, 1284 (912–1520) long, 246 (176–320) wide at haptoral region. Clamps four pairs, of equal size, 22 (20–24) long, 28.5 (28–32) wide, arranged symmetrically and equidistantly in posterior third of body, embedded in body proper, anterior pair at distance of 884 (592–1136) from anterior end. Clamp structure typical of Mazocraeoides , closed type, comprises five sclerites: SAA thin formed by fusion of two sclerites, SAS cup - shaped, SMB broad, perforated by apertures, SMS rectangular, labiatum U-shaped with pointed tips. Lappet not differentiated. Posterior part of body with two pairs of anchors and one pair of hooks; outer pair of anchors 36 (28–40) long with short wide shaft, short triangular spur and pointed tip; inner pair 12.5 (12–16) long, narrow; hooks narrow, rod-shaped, 8 long. Prohaptor with one pair of suckers, each 20x 12 in size. Pharynx oval, 40 long, 24–28 wide. Esophagus long, posterior part flanked by prominent gland cells arranged in two groups, ducts from glands extend anteriorly. Ceca long, broad with lateral branches, extend almost to posterior end of body.

Genital pore median, at a distance of 148 (100–192) from anterior end. Testis single, elliptical, major part (2/3rds) enclosed in haptoral zone, anterior third projecting anterior to haptoral zone. Genital complex small, oval, 25 (20–28) x 20 (16–24), armed with one pair of long needle-like lateral hooks and five pairs of pointed median hooks arranged in two groups.

Ovary elongate, 222 (176–268) long, anterolateral to testis, extends only slightly into haptoral zone. Mehlis’s gland dorsal to germinal portion of ovary. Uterus in midline ventral to spermduct.

Single egg in uterus oval, 110 x 56 in size. Vitelline follicles numerous form two lateral zones extend from bifurcation point to cecal ends. Vitelline reservoir Y-shaped, in midline, anterior to ovary. Vagina not observed.

Remarks: This species differs from all the other known species of Mazocraeoides by possessing the following combination of characters: The haptoral clamps are restricted to posterior third of the body, embracing only the posterior part of testis, the anterior part of testis and ovary lying anterior to this zone and the genital complex comprising one pair of long needle-like lateral hooks and five pairs of median hooks. It is most similar to Mazocraeoides gonialosae Tripathi,1957 reported from the Ganges river gizzard shad, Gonialosa manmina (Hamilton) but the latter has clamps extending anteriorly up to the midbody and both the testis and ovary are within the haptoral zone. The new species also shows some resemblance to M. georgei but the latter differs in the location of the testis and ovary in the haptoral zone, the shape of the anchors, number of hooks within the genital complex and in having eggs with filaments at both polar ends.

Figures

FIGURES 5–9. Mazocraeoides fusiformes n. sp. 5. Entire worm, ventral view; 6. Genital atrium; 7. Clamp; 8. Isolated sclerites of haptoral clamp; 9. Anchors and hooks. Scale bars: Fig. 5, 200µm; Figs. 6–8, 10µm; Fig. 9, 30µm.