Raosentis is a genus of Acanthocephala (thorny-headed worms, also known as spiny-headed worms) that parasitize the intestine of fish.
| Raosentis | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Acanthocephala |
| Class: | Eoacanthocephala |
| Order: | Gyracanthocephala |
| Family: | Quadrigyridae |
| Subfamily: | Pallisentinae |
| Genus: | Raosentis Datta, 1947 |
Taxonomy edit
Description edit
The genus Raosentis is characterized by the trunk spines are restricted to anterior region only (not divided into two separate regions). The anterior trunk has 16-17 circles of spines and 4 circles of proboscis hooks with anterior two circles larger than posterior two circles; and a spineless space between 2nd and 3rd circles. Species in the genus have a small fusiform body with small hypodermic nuclei arranged in 4 or 5 pairs dorsally and 1 or 2 ventrally. The proboscis is globular to elongate with four circles of proboscis hooks, anterior two circles of hooks longer and shorter than posterior two circles with hookless free space in between. The proboscis sheath is single layered with ganglion at base. The Anterior trunk has 16-17 circles of rose-thorn spines. Testes contiguous, tandem, and near the posterior extremity. Cement gland syncytial with 8-10 nuclei. Vagina has two sphincters. Eggs are small and elliptical. Species are distinguished by 1. Ratio of size of proboscis hooks.[1]
| Female measurements (mm) | ||||||
|---|---|---|---|---|---|---|
| Measurements | R. cavasii | R. dattai[1] | R. godavarensis | R. ivaniosi[1] | R. podderi [1] | R. thapari[1] |
| Length of proboscis | ||||||
| Width of proboscis | ||||||
| Length of proboscis receptacle | ||||||
| Width of proboscis receptacle | ||||||
| Length of trunk | 1.54-2.74 | 2.0-7.0 | ||||
| Width of trunk | 0.45-0.90 | 0.85-2.0 | ||||
| Length of small rootless spines | ||||||
| Length of lemnisci | ||||||
| Size of eggs | 0.040-0.045 x 0.02-0.022 | 0.040-0.060 x 0.020-0.030 | 0.039-0.04 x 0.02-0.022 | |||
| Male measurements (mm) | ||||||
| Length of proboscis | ||||||
| Width of proboscis | ||||||
| Length of proboscis receptacle | ||||||
| Width of proboscis receptacle | ||||||
| Length of trunk | 1.5-5.0 | |||||
| Width of trunk | 0.3-0.67 | |||||
| Length of small rootless spines | ||||||
| Length of lemnisci | ||||||
| Size of anterior testis | ||||||
| Size of posterior testis | ||||||
| Size of cement glands | 0.21-0.25 x 0.18-0.20 | 0.120-0.200 x 0.200-0.250 | 0.32-0.52 × 0.16-0.35 | 0.28–0.33 × 0.13–0.20 | ||
Species edit
There are six valid species in the genus Raosentis.[2][3][4]
- Raosentis cavasii Gupta 2021[4]
Found infesting Mystus cavasius and named after the host of the species cavasius.[4]
- Raosentis dattai Gupta and Fatma, 1986[5]
R. dattai was found infesting the intestine of the Eutropiichthys vacha in the Gomti river in Lucknow. Male has a small body small with hypodermic nuclei 4-5 pairs dorsally and 2-3 pairs ventrally, 2.68 x 0.7 Proboscis 0.24 x 0.18.· armed with 4 circles of hooks arranged in 6,6,8,8 per row. 1st circle of hooks 0.060-0.065; 2nd 0.055-0.058; 3rd 0.020-0.025. Proboscis sheath 0.61 x 0.15. L/I--O.70 x 0.10; L/2--O.75 x 0.08. Anterior trunk spines extending up to anterior testes. T /1--0.34 x 0.32; T /2--0.32 x 0.28. Eggs are oval.[1]
- Raosentis godavarensis Vankara and Vijayalakshmi, 2009[6]
Found infesting the striped dwarf catfish (Mystus vittatus) and named after the river it was found Godavari.[6]
- Raosentis ivaniosi George and Nadakal, 1978[7]
R. ivaniosi was found infesting the small intestine of the Flatmouth sea catfish (Arius platystomus) in Veli Lake, Puvar and Vellayani, Kerala. Proboscis 0.110-0.160 x 0.040-0.075, armed with 4 circles of 8-10 hooks each, 1st and 2nd circles larger and stouter than 3rd and 4th circle s, larger hooks of 1st circle 0.060-0.090 x 0.004-0.008; 2nd 0.050-0.058 x 0.004-0.007; 3rd 0.030-0.046 x 0.003-0.005; 4th 0.024-0.035 x 0.002-0.005; roots of 1st and 2nd circles of hooks 0.016-0.018. L/1-O.370-0.380 x 0.020-0.040; L/2-D.300-0.350. Proboscis sac 0.180-0.200; T /1-0.200-0.260 x 0.175-0.250; T /2-D.300-0.350 x 0.200-0.300.[1]
- Raosentis podderi Datta, 1947
It is the first species to be described in the genus Raosentis and is the type species.[2] It was found infesting the small intestine of Mystus cavassius and intestine of the striped dwarf catfish (Mystus vittatus) in river Godavari. Body 1.70–2.76 × 0.37–0.47; proboscis 0.32–0.42 × 0.07–0.075; large hooks 0.66; smaller hooks 0.01; leminsci 0.38–0.42 × 0.04–0.07; testes 0.25-0.28 × 0.20–0.24; cement reservoir 0.15–0.23 × 0.12–0.16 and eggs 0.04-0.05 × 0.02–0.022. [6] Original description from Datta (1947 ) : Male: Body 0.67-2.37. Proboscis hooks 6 in 1st and 2nd circle; 7 in 3rd and 4th circle. hypodermal nuclei 2 dorsal and 1 ventral. anterior trunk spines in 16-17 circles. Cement gland cyncytial with 8-10 nuclei Female: Body 1.31-2.53. Two tubular vagina. Eggs 0.050 x 0.020.[1]
- Raosentis thapari Rai, 1967[8]
'R. thapari distinguished from R. podderi mainly on the number of hypodermic nuclei on dorsal and ventral trunk. It was found infesting the small intestine of the striped dwarf catfish (Mystus vittatus) in river Godavari (Gorakhpur. Mathura) and the freshwater Zig-zag eel (Mastacembelus armatus). Body 1.18–1.58 × 0.27–0.32; proboscis 0.28–0.32 × 0.07– 0.21; larger hooks 0.06; smaller posterior hooks 0.01–0.02; leminsci 0.30-0.38 × 0.09–0.10; testes 0.15–0.27 × 0.13– 0.18; cement reservoir 0.11–0.16 × 0.09–0.15; eggs 0.03-0.04 × 0.02–0.022.[6] Egg length also given as 39.5 with an elongation ratio of 1.88.[9] Older measurements from Rai (1967) found the male with a Body size of 1.7-2.37 x 0.57-0.68. Proboscis 0.14-0.24 x 0.11-0.16, armed with 4 circles, anterior two circles with 6 hooks each, while, posterior two circles with 8 hooks each, non-spined area between 2nd and 3rd circles 0.058-0.078. 1st circle of hooks 0.085; 2nd 0.058; 3rd 0.028; 4th 0.020. Trunk spines anterior with 9 rows of 25-30 each. Proboscis sac 0.39-0.56 x 0.097-0.11, ganglion at base. Lemnisci equal, 0.55 x 0.075, hypodermic nuclei dorsally and ventrally 3 pairs. T /1-0.25-0.27 x 0.27-0.5. T /2- 0.26-0.33 x 0.31-0.35.[1]
Hosts edit
The life cycle of an acanthocephalan consists of three stages beginning when an infective acanthor (development of an egg) is released from the intestines of the definitive host and then ingested by an arthropod, the intermediate host. Although the intermediate hosts of Gyracanthocephala are not known, the order Gyracanthocephala often has Crustaceans as the intermediate host. When the acanthor molts, the second stage called the acanthella begins. This stage involves penetrating the wall of the mesenteron or the intestine of the intermediate host and growing. The final stage is the infective cystacanth which is the larval or juvenile state of an Acanthocephalan, differing from the adult only in size and stage of sexual development. The cystacanths within the intermediate hosts are consumed by the definitive host, usually attaching to the walls of the intestines, and as adults they reproduce sexually in the intestines. The acanthor are passed in the feces of the definitive host and the cycle repeats. Although paratenic hosts (hosts where parasites infest but do not undergo larval development or sexual reproduction) are found in the order Gyracanthocephala, none have been described for Raosentis species.[11]
Raosentis species infest fish.
- Hosts for Raosentis species
-
The Zig-zag eel is a host for R. thapari
Notes edit
References edit
- ^ a b c d e f g h i Title Handbook on Indian Acanthocephala Author Subhendu Bikas Bhattacharya Contributor Zoological Survey of India Publisher Zoological Survey of India, 2007 Original from University of Chicago Digitized 15 Sep 2010 ISBN 8181711386, 9788181711380 Length 225 pages https://faunaofindia.nic.in/PDFVolumes/hpg/027/index.pdf
- ^ a b Amin, O. M. (2013). "Classification of the Acanthocephala" (PDF). Folia Parasitologica. 60 (4): 275. doi:10.14411/fp.2013.031. PMID 24261131. Archived (PDF) from the original on 10 August 2017. Retrieved 27 September 2019.
- ^ "Raosentis Hamann, 1892". www.itis.gov. Integrated Taxonomic Information System (ITIS). 1 September 2019. Retrieved 1 September 2019.
- ^ a b c GUPTA, S. (2021). METAZOAN PARASITES OF Mystus cavasius (HAMILTON) OF RIVER GOMTI WITH DESCRIPTION OF A NEW SPECIES OF ACANTHOCEPHALA Raosentis cavasii sp. nov. Uttar Pradesh Journal of Zoology, 69-72.
- ^ R. dattai Gupta and Fatma, 1985: Indian J. Helmint"', 37(2) : 149-180.
- ^ a b c d Vankara, A. P., & Vijayalakshmi, C. (2009). Metazoan parasites of Mystus vittatus (Bloch) of River Godavari with description of a new species of Acanthocephala, Raosentis godavarensis sp. nov. Journal of parasitic Diseases, 33, 77-83.
- ^ George, P. V., & Nadakal, A. M. (1978). Two new species of Acanthocephala from marine fishes of Kerala. Aquatic Biology, 3, 91-97.
- ^ R. thapari Rai, 1967 : Ind.l.He/millth. 19(1); pp. 27-44. Type locality: Gorakhpur, U.P.
- ^ https://via.library.depaul.edu/cgi/viewcontent.cgi?article=1273&context=csh_etd
- ^ CDC’s Division of Parasitic Diseases and Malaria (April 11, 2019). "Acanthocephaliasis". www.cdc.gov. Center for Disease Control. Retrieved July 17, 2023.
- ^ Schmidt, G.D. (1985). "Development and life cycles". In Crompton, D.W.T.; Nickol, B.B. (eds.). Biology of the Acanthocephala (PDF). Cambridge: Cambridge Univ. Press. p. 273–305.