Arch. Protistenk. 124 (1981): 391 ~397

Department of Zoology, Marathwada University, Aurangabad,

Maharashtra, India

Observations on the Rectal Flagellates of Indian Amphibians.I. Genus: Hexamiius DUJARDIN, 1838

By R. KRISHNAMURTHY and S. G. SHETE

With 11 Figures

Summary

The paper described two new species of flagellates of the genus Hexamitus DUJARDIN, 1838

from anuran amphibians in India, namely H. cyanophlycti n. sp. from Rana cyanophlyctis and H.

melanosticti n. sp. from Bufo melanosticius, The former is characterised by slender and uniformly

tubular axostyles and small separated nuclei. The latter has filamentous axostyles passing through

two characteristic chromatic rings near the posterior end and small, spherical and distinctly sepa­

rated nuclei.

Introduction

A survey of the rectal protozoa of three species of frogs and toads in MaharashtraState was carried out between 1976 and 1978. Besides several ciliates and opalinatesthese hosts showed presence of numerous flagellate species. This communicationgives an account of two of these flagellates belonging to the genus Hexamitus, DUJAR­DIN, 1838.

Material and Methods

The fecal contents of the rectum were diluted with 0.7% normal saline and examined forpresence of flagellates. Permanent preparations were made both by dry and wet methods. Thedry smears were fixed in methanol and stained with GIEMSA'S stain. The wet smears were fixedin SCHAUDINN'S fluid and stained with phosphotungstic haematoxilin. The drawings were made

with the help of a camera lucida at a magnification of 2,000 x. Measurements were based on a

count of 50 organisms.

Results

Hexamitus cyanophlycti n. sp. (Figs. 1-6)

This flagellate was observed in the rectal contents of frog, Rana cyanophlyctis,collected from the suburbs of Aurangabad. The infection was heavy and the flagel­lates were associated with those of the genera M onocercomonas and Tritrichomonas.

Morphology: The flagellates are typically pyriform (Figs. 2, 4, 5) or oval (Fig. 1)in shape. The periplast is very thin.

392 R. KRISHNAMURTHY and S. G. SHETE

1

5)I

6

Figs. 1- 6. H eeamitu« cyanophlycti n. sp.Fig. 1. An oval form showing unequal caudal flagella and convergent axostyles.Fig. 2. A pyriform individual showing parallel axostyles, spherical separated nuclei and acrone­

matic flagella.Fig. 3. Showing general structure.Fig. 4. Showing unequal anterior flagella and separated nuclei.Fig. 5. Showing convergent axostyles, fused nuclei and acronematic flagella.

Fig. 6. Showing unequal anterior flagella and parallel axostyles,

Rectal Flagellates of Indian Amphibians. 1. 393

Two blepharoplasts, separated from one another, are situated at the anterior endof the body. The granules give origin to the mastigont elements comprising of threepairs of anterior flagella and a pair of axostyles running through the body and con­tinuing behind as the caudal flagella. The anterior flagella are distinctly unequal inlength (Figs. 3-6) and measure one and a half to two times the length of the body.The caudal flagella are also unequal (Figs. 1,2,5) and measure about one and a halftimes the length of the body. In general, the flagella of one side appear to be slightlylonger than those of the other (Figs. 3, 6). The flagella are acronematic in many cases(Figs. 1, 2, 3, 5).

The axostyles are slender, tubular and run backwards somewhat parallel to oneanother (Figs. 2, 6) or slightly covergent (Figs. 1, 4, 5). They are uniform in diameterthrought their length and are separated by a maximum distance of 1.7 [tm on anaverage.

The two nuclei are relatively small and spherical (Figs. 2,4) or ovoidal (Figs. I, 3,6) in shape. They are distinctly separated from one another (Figs. 1-4) or partiallyfused (Fig. 5).

The cytoplasm stains homogenously and contains very few granular inclusions.

The dimensions of the parasite are as follows: (All measurements are in microns)

Sr. No. Particulars Minimum Maximum Average

1. Length of the body 6.1 13.2 7.9

2. Maximum breadth of the body 4.2 11.3 6.4

3. Distance between the two axostyles 0.5 5.2 1.8

4. Length of the right anterior flagellum I 7.0 16.0 11.9

5. Length of the right anterior flagellum II 8.0 17.4 13.26. Length of the right anterior flagellum III 9.9 21.2 15.2

7. Length of the right caudal flagellum 7.5 17.4 12.9

8. Length of the left anterior flagellum I 7.0 16.9 11.9

9. Length of the left anterior flagellum II 8.0 17.4 13.0

10. Length of the left anterior flagellum III 8.5 19.3 14.9

11. Length of the left caudal flagellum 7.1 lfi.4 11.7

12. Size of the nucleus 0.9 X 0.9 2.3 X 1.9 1.5 X 1.2

Discussion: Six species of the genus Hexamiiue are reported from amphibiansso far. These are:

1.

2.3.4.5.6.

H. intestinalis

H. ooatus

H. batrachorum

H. hoarei

H. ranae

H. mhaisekari

DUJARDIN,1841

SWEZY, 1915

SWEZY, 1915

KRISHNAMURTHY, 1967

KRISHNAMURTHY and MADItE (under publication)

KRISHNAMURTHY and MADRE (under publication)

Of these H. ranae is described from the same host and same locality as the presentspecies. However the two are distinguished by a number of characters. The present

394 R. KRISHNAMURTHY and S. G. SHETE

species has slender, tubular axostyles of uniform diameter, contrasted with the axo­styles of H. ranae, which are tubular and funnel shaped in the anterior half and solidand rod like in the posterior half. The nuclei of the present species are generally sepa­rated from one another while those of the latter species are in most cases partlyor fully fused.

Compared with the rest of the species, it is larger in size than H. batrachorum butsmaller than the others. It is contrasted from H. mhaisekari by the presence of tubularaxostyles as against the rod like in that species and by its nuclei being separatedfrom one another. It is marked off from H. hoarei by its tubular axostyles as againstthe filamentous ones of that species. Also the characteristic chromatic ring throughwhich the axostyles pass near the posterior end of the body in the case of H. hoareiare absent here. The two nuclei being separated from one another distinguishes thisspecies from H. ovatus. The two groups of chromatic granules present near the pos­terior ends of the axostyles in H. batrachorum are absent here. This species has muchshorter caudal flagella than H. intestinalis which has caudal flagella more than thricethe body length. Further the axostyles are tubular here and rod like in that species.

In view of these differences, this species is considered distinct and named Hexami­tus cyanophlycti n. sp., after the specific name of the host.

SpeciesHostHabitatLocality

Hexamitus cyanophlycti n. sp.Rana cyanophlyctis

RectumAurangabad, Maharashtra, India.

Hexamitus melanosticti n. sp. (Figs. 7-11)

This flagellate was collected from the rectum of the toad, Bufo melanostictus. Itwas associated with another species of Hexamitus (described in the following pages)sa well as flagellates of the genera Monocercomonas and Tritrichomonas.

Morphology: The parasite is typically spherical or ovoidal and occasionallysomewhat pyriform in shape. It has a considerably broad body covered over by adelicate periplast (Figs. 9-II).

Two distinctly separated blepharoplasts are situated close to the anterior end,giving rise to the mastigont elements. The three pairs of anterior flagella are slightlyunequal and a little longer than the body (Figs. 7, 8, 10). The caudal flagella aredistinctly unequal (Figs. 8, II) the shorter flagellum being about as long as body andthe longer one up to one and a half times the body length. Many of the flagella areacronematio (Figs. 7, 9, 10).

The axostyles are distinctly filamentous, being almost of the same thickness asthe flagella (Figs. 8-11). They run backwards almost parallel or slightly convergentand continue as the caudal flagella. They are separated by a distance of about 1.9 [tm

on an average. Near the posterior end of the body, the two axostyles pass throughtwo characteristic ring-like structures before continuing into the caudal flagella(Figs. 9, 10, II). The presence of two chromatic rings around the axostyles is extremely

Rectal Flagellates of Indina Amphibians. 1. 395

9

11

8

10

10,um

Figs. 7 -11. H examitus melanosticti

Fig. 7. Showing general structure.

Fig. 8. Showing unequal Ilagella, filamentous axostyles and separated nuclei.

Fig. 9. Showing chromatic rings, vacuoles and acronematic flagella.

Fig. 10. Showing chromatic rings, vacuoles, unequal and acronematic flagella and spherical nuclei.

396 R. KRISHNAMURTHY and S. G. SHETE

characteristic of this species. Also chacrateristic is the presence of two elongatedvacuoles between the axostyles in the anterior half (Figs. 7-11).

The two nuclei are again very characteristic in being small, spherical and distinctlyseparated from one another (Figs. 8-10). The nuclei measures lflm in diameter onan average.

The cytoplasm stains homogenously and shows few granular or vacuolar inclusions.

The dimensions of the parasite are as follows: (All measurements are in microns).

Sr. No. Particulars Minimum Maximum Average

1. Length of the body 7.5 10,4 9.12. Maximum breadth of the body 5.7 9.9 7.33. Distance between the two axostyles 0.5 3.3 1.94. Length of the right anterior flagellum I 8.9 14.6 11.05. Length of the right anterior flagellum II 9.9 17.4 12.36. Length of the right anterior flagellum III 11.3 24.0 13.97. Length of the right caudal flagellum 5.6 24.5 10.98. Length of the left anterior flagellum I 8.5 14.6 11.29. Length of the left anterior flagellum II 10,4 17,4 12.4

10. Length of the left anterior llagellum III 10,4 24.0 14.611. Length of the left caudal flagellum 8.9 26.4 14.212. Diameter of the nucleus 0.9 1.2 1.0

Discussion: This species is unique in having the two filamentous axostyles pass­ing through two distinct chromatic rings near the posterior end of the body. While achromatic ring is described in H. hoarei, the nature is different. Here there are tworings one around each axostyle, contrasted with the condition in H. hoarei whereboth the axostyles pass through a single ring. In the rest of the species the axostylesare either tubular or rod-like, or a combination of both, as compared with the fila­mentous ones here.

The presence of relatively small and spherical nuclei distinctly separated from oneanother and the presence of two elongated vacuoles between the axostyles in theanterior half of the body are also characters which are unique to this species.

In view of these numerous characters, which are peculiar to this species, it is con­sidered different from all the other species and named Hexamitus melanosticti n. sp.,after the specific name of the host.

SpeciesHostHabitatLocality

Hexamitus melanosticti n. sp.Bufo melanoetictus

RectumAurangabad, Maharashtra, India.

The slides of the type material of all the two species described are deposited inthe Protozoology Section, Department of Zoology, Marathwada University, Auran­gabad.

Rectal Flagellates of Indian Amphibians. 1.

Acknowledgement

397

The authors are thankful to Dr. R. NAGABHUSHANAM for providing the facilities and for hisencouragemen t,

Literature

DUJARDIN, F.: Historic naturelle des zoophytes. Infusoires. Paris 1841.KRISHNAMURTHY, R.: Hexamiiue hoarei n. sp., A new diplomonad flagellate from the frog in India.

Riv. Parassit. 28 (4) (1967): 233-237.

SWEZY, 0.: On a new trichomonad flagellate, Trichomitus parvu8, from the intestine of Amphib­ians. Univ. Calif. Pub!. Zoo!' 16 (1915): 89-94.

KRISHNAMURTHY, R., and MADRE, V. E.: The description of two new species of the genus Hexami­ius DUJARDIN, 1838 from the frogs in India. (Under publication.)

Authors' address: Dr. R. KRISHNAMURTHY and S. G. SHETE, Department of Zoology, Marath­wada University, Aurangabad - 431004, India.