Synopsis of Biological Data on the Tor Mahseer Tor Tor (Hamilton, 1822)
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ISSN 0014-5602 FAO Fisheries Synopsis No. 158 SYNOPSIS OF BIOLOGICAL DATA ON THE TOR MAHSEER Tor tor (Hamilton, 1822) FAO Fisheries Synop sis No. 158 FIR/S158 SAST - Tor tor x,xx(xx)xxx,xx SYN OP SIS OF BI O LOG I CAL DATA ON THE TOR MAHSEER Tor tor (Ham il ton, 1822) Pre pared by V.R. Desai Cen tral In land Cap ture Fish eries Re search In sti tute (I.C.A.R.) Barrackpore: West Bengal IN DIA FOOD AND AG RI CUL TURE OR GA NI ZA TION OF THE UNITED NA TIONS ROME, 2003 The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. ISBN 92-5-104933-5 All rights reserved. Reproduction and dissemination of material in this information product for educational or other non-commercial purposes are authorized without any prior written permission from the copyright holders provided the source is fully acknowledged. Reproduction of material in this information product for resale or other commercial purposes is prohibited without written permission of the copyright holders. Applications for such permission should be addressed to the Chief, Publishing Management Service, Information Division, FAO, Viale delle Terme di Caracalla, 00100 Rome, Italy or by e-mail to [email protected] © FAO 2003 FIR/S158 Tor tor iii PREP A RA TION OF THIS SYN OP SIS The pres ent docu ment was included in the FAO Spe cies Series in view of the impor tance of Tor tor as a food and game fish of India. This paper is based on data col lected by the author and on infor ma tion compiled from vari ous other sources. The syn op sis was pre pared by the au thor with the assis tance of N. P. Shrivastava and K. Manjhi of the Res er voir Fish eries Re search Cen tre of the Central Inland Cap ture Fisheries Re search In stitute, Hoshangabad (Madhya Pradesh), In dia. AC KNOWL EDGE MENTS I am highly indebted to the Food and Agriculture Organization of the United Nations for giving me the opportunity of writing this Synopsis and reaching an international audience. I am also grateful to the Director of Central Inland Capture Fisheries Research Institute (CICFRI), Barrackpore (West Bengal) for permitting me to do this task. I will be failing in my duty if I forget to acknowledge the valuable guidance received from Shri. S.J. Karamchandani, the then Officer-In-Charge, Narmada Tapti unit of CICFRI, Hoshangabad (Madhya Pradesh) while carrying out the work on biological studies on Tor tor (Hamilton, 1822) from Narmada River. Special gratitude is due to my son Chandrakant Desai and his staff for their remarkable help in final typing and submitting the Synopsis and taking care of correspondence with FAO. This work, utilized for my Ph.D. thesis and later included in this synopsis, constitutes the main part of the publication. I am also thankful to the entire staff of Narmada-Tapti Unit for helping me in collection and analysis of data in the field and laboratory. Pro ject Man ager: M. Lamboeuf, J. Lleonart (FAO, Rome) and P. Ol iver (IEO, Palma de Mallorca). Tech ni cal Ed i tor: T. Petr, Toowoomba QLD 4350, Austra lia. Sci en tific Re viser: N. De Angelis (FAO, Rome). Sci en tific Il lus tra tor: E. D’Antoni (FAO, Rome). Page Com po si tion: G. Sciarappa Demuro and M. Kautenberger-Longo (FAO, Rome). Cover Il lus tra tion: E. D’Antoni (FAO, Rome). Desai, V.R. Syn op sis of bi o log i cal data on the tor mahseer Tor tor (Ham il ton, 1822). FAO Fisheries Synopsis. No. 158. Rome, FAO. 2003. 36p. AB STRACT Among Indian mahseers, Tor mahseer Tor tor (Hamilton, 1822) is the most important food and game fish of India after Tor putitora (Hamilton, 1822). It constitutes an outstanding fishery in the Narmada River in central India. It has also settled in some Indian reservoirs which have been stocked with this fish. However, the building of dams across certain rivers has created reservoirs that have destroyed the natural breeding grounds of the fish and caused mortality of brood and juvenile fish indiscriminately. The mahseer fishery of India is further declining as a result of low recruitment of the fish. Stocking rivers and reservoirs with mahseer is therefore essential to restore the fishery. This synopsis is the compilation of biological data for Tor tor – Tor mahseer collected from different sources. The detailed biological information on Tor tor, including the feeding habits, breeding and growth patterns contained in this synopsis, will be useful in planning the development of the mahseer fishery in India. Dis tri bu tion: Au thors FAO Fisheries Offi cers Re gional Fish eries Coun cils and Com mis sions Se lec tor SC click for next page click for previous page FIR/S158 Tor tor v TA BLE OF CON TENTS Page IN TRO DUC TION ................................................1 1. IDEN TITY ..................................................1 1.1 No men cla ture .............................................1 1.1.1 Sci en tific name .........................................1 1.1.2 Syn onyms ............................................1 1.1.3 Et y mol ogy and com mon names .................................1 1.2 Tax on omy ...............................................1 1.2.1 Def i ni tion .............................................1 1.2.2 Author of generic name .....................................2 1.2.3 De scrip tion............................................2 1.2.4 Gen eral vari abil ity ........................................3 1.2.5 Key to the In dian and Sri Lankan spe cies of ge nus Tor ....................4 1.3 Mor phol ogy ..............................................4 1.3.1 Ex ter nal mor phol ogy ......................................4 1.3.2 Pha ryn geal teeth ........................................5 1.3.3 Hypobranchial skel e ton .....................................6 1.3.4 Ad re nal gland ..........................................6 2. DIS TRI BU TION ...............................................6 2.1 Total area ...............................................6 2.2 Dif fer en tial dis tri bu tion .........................................7 2.2.1 Spawn, larvae and ju ve niles ..................................7 2.2.2 Adults ..............................................7 2.3 De ter mi nants of dis tri bu tion ......................................8 2.4 Hy brid iza tion ..............................................8 2.4.1 Hy brids .............................................8 2.4.2 Nat u ral hy brid iza tion* ......................................8 3. BIONOMICS AND LIFE HISTORY .....................................8 3.1 Re pro duc tion .............................................8 3.1.1 Sex u al ity .............................................8 3.1.2 Ma tu rity .............................................9 3.1.3 Mating ..............................................9 3.1.4 Fer ti li za tion ...........................................9 3.1.5 Go nads .............................................9 3.1.6 Spawning ............................................11 3.1.7 Spawn .............................................12 3.2 Pre-adult phase ...........................................13 3.2.1 Em bry onic phase ........................................13 3.2.2 Lar val phase ..........................................13 3.2.3 Ad o les cent phase .......................................14 3.3 Adult phase (mature fish) ......................................16 vi FIR/S158 Tor tor 3.3.1 Lon gev ity ............................................16 3.3.2 Har di ness ...........................................16 3.3.3 Com pet i tors ..........................................16 3.3.4 Pred a tors ............................................16 3.3.5 Par a sites, dis eases, in ju ries and ab nor mal i ties ........................16 3.4 Nu tri tion and growth .........................................17 3.4.1 Feeding (time, place, manner, sea son) ............................17 3.4.2 Food ..............................................17 3.4.3 Growth rate ...........................................19 3.4.4 Me tab o lism* ..........................................21 3.5 Be hav iour ...............................................21 3.5.1 Mi gra tion and lo cal move ments ................................21 3.5.2 Schooling ............................................21 3.5.3 Re sponse to stimuli* ......................................21 4. POP U LA TION (STOCK) .........................................21 4.1 Struc ture ...............................................21 4.1.1 Sex-ra tio ............................................21 4.1.2 Age com po si tion ........................................22 4.1.3 Size com po si tion ........................................22 4.2 Abun dance and den sity (of pop u la tion)* ...............................23 4.3 Na tal ity and re cruit ment .......................................23 4.3.1 Re pro duc tion rates* ......................................23 4.3.2 Fac tors af fect ing re pro duc tion* ................................23 4.3.3 Re cruit ment ..........................................23 4.4 Mor tal ity and mor bid ity ........................................23 4.4.1 Mor tal ity rates .........................................23 4.4.2 Fac tors caus ing or af fect ing mor tal ity .............................23 4.4.3 Fac tors af fect ing mor bid ity* ..................................23