The Food of the Himalayan Newt Tylototriton Verrucosus (Anderson): a Preliminary Study

2005·1.4 MB·

by  N Thambalshangbi Devi

.
Journal of the Bombay Natural History Society, 102 (2), May-Aug 2005 166-168
THE FOOD OF THE HIMAEAYAN NEWT TYLOTOTRITON VERRUCOSUS
(ANDERSON): A PRELIMINARY STUDY
1
N.Thambalshangbi Devi2
'Accepted February 2004
^Department of Zoology, D.M. College of Science, Imphal 795 001, India. Email: [email protected]
The present study investigates the diet of the Himalayan Newt Tylototriton verrucosus (Anderson) based on the
specimenscollectedfromUkhrul andSenapati districtsofManipur. Barring sporadicreportsontheoccurrenceofthis
species in this region, no detailed studies have been reported. The present study aims at examining the types offood
materialconsumedbythisanimalonthebasisoftheirgutcontents.Thefooditemsofthespecimenscollectedbetween
AprilandOctober 1996consistedofinsects,insectlarvae,millipedes,spiders,scorpions,molluscs,plantandinorganic
matter,includingpebbles,sandandmud,whichareincidentally ingestedalongwiththefood.
Keywords: gut,mollusc,Lengva pebble,swampy area,chara
,
INTRODUCTION photographed and grouped as follows: 1. Insects: (a) Insect
fragments,namelyhead,dissociatedlegsandwings,(b)Larvae
The Himalayan Newt Tylototriton verrucosus ofdifferent typesofinsects; 2. Nematodes; 3. Millipedes; 4.
(Anderson) (Lengva in Tangkhul) is found in Ukhrul and Scorpions;5.Spiders;6.Molluscs;7.EggsofHimalayanNewt.
Senapati, the hill districts of Manipur (including the Siroi- They were further identified using diagnostic taxonomic
KasomHillrangeofUkhruldistrict,whichextendsuptoMao characters.
ofSenapatidistrict),ataltitudesfrom 1,500to2,200mabove
msl. RESULTS
T. verrucosusisfoundinsmall numbersinsmallwater
pools and swampy areas ofthe northern and eastern hills of The number of Himalayan Newts collected between
Manipur. Except Nair (1996), who stated that it feeds on April and October 1996 and the prey recorded are given in
aquatic vegetation, insect larvae, tadpoles and earthworms, Table 1
no detailed information on the food items of this animal is The primary fooditem ofthe newt wasinsects, which
available.Thispaper, therefore, aimsto investigate thefood were identified using Richards and Davies (1977), Riley
items of T. verrucosus collected from Ukhrul (Hundung, (1977) and Zanetti and Adriano (1977). The guts of the
Siroi, Kasom) and Senapati districts (Oinam Ching) of dissectednewtscontainedscorpions,spiders(6spiderswere
Manipur. found in one individual), nematodes, millipedes, molluscs,
andeggsofHimalayanNewts(Table 1). 25 HimalayanNewt
MATERIALAND METHODS eggs were found once in the gut of an individual, and
21 eggs were found in another. The eggs per gut range
Analysis of the gut (stomach and large intestine) between 6-10. The newts start consuming eggs from June
content of T. verrucosus was carried out between April and (see Table 1). No egg was found in the gut contents after
October 1996. Duringthisperiod,theanimalswerecollected August.
andstoredinplasticbottles,containing 10ml chloroformand Materials found in the guts otherthan those described
thereafter 5% formaldehyde solution was injected into the above are plants such as Blue GreenAlgae, pieces ofstraw
stomach ofeach animal to preserve the organs and to check and chara (Table 1). The newt feeds on a variety ofinsects
furthermixing ofthe foodparticles with gastricjuice. In the belonging to different orders; Honey Bees (Table 2) were
laboratory, the specimens were grouped on the basis ofthe consumedinlargenumbers(22.29%)(Fig. 1).
month ofcollection. The stomach and the large intestine of ThefooditemsconsumedbyT. verrucosus(Anderson)
each animal were removed and preserved separately in appear to be dependant on the availability of insects and
70%alcohol. other organisms in the area during a specific period of the
The guts were later dissected longitudinally and their year.April marksthebeginningofthewarmseason,whichis
contents transferred to a petridish containing 70% alcohol. usually punctuated by sporadic rains. Before the onset of
The contents were examined under a microscope, and later heaviermonsoon rains in June, the flowering ofthe number
'
FOOD OF THE HIMALAYAN NEWT TYLOTOTRITON VERRUCOSUS
Table 1: Month-wise numberof Himalayan Newtsandtheirprey
SI.No. April May June July Aug. Sept. Oct. Totalnumberof
newts
1 Total No. of Newtsexamined 14 17 23 18 11 5 3 91
2 Guts with contents 9 15 19 17 8 4 2 74
3 Emptyguts 5 2 4 1 3 1 1 17
4 Gutscontainingpebble,sandandmud - - - - - - 1 1
5 Gutscontainingplantmaterials - 1 1 1 - 2 - 5
6 Gutscontainingeggs - - 1 4 3 - 8
7 Gutcontainingscorpion - - - - - - 1 1
8 Gutscontainingspider - 1 1 - - - - 2
9 Gutcontainingnematodes - - - - - 1 - 1
10 Gutscontainingmolluscs - 2 2 - - - - 4
11 Gutscontainingmixed items - - 4 6 1 - - 11
12 Gutscontaininginsects 9 11 10 6 4 1 - 41
ofshrubs and many fruit-bearing plants ofthe areaattracts a DISCUSSION
largenumberofinsects.Withtheonsetofheavyrainsaquatic
plants and insects are plentiful in the habitat. Many ofthese Thisstudy indicatesthatT. verrucosusfeedson insects
insects form the food items ofthe newt. belongingtoseveral Orders. The food itemscontainedin the
Table2: Types andquantityofinsectsfound inthegutsofHimalayan Newt
SI.No. Insect Total
Order Insect Months (%)
April May June July Aug. Sept. Oct.
1 Odonata (a) Dragonfly 2 1 - - 2 - 5(3.18)
2 Orthoptera (a) Grasshopper 2 1 1 1 1 - 6(3.82)
(b) PrayingMantis 1 2 - 2 - - 5(3.18)
3 Hemiptera
(a) Heteroptera Plantbug - 5 3 3 - - 11 (7.00)
(b) Homoptera Planthopper - 7 2 3 1 - 13(8.28)
4 Coleoptera (a) Beetles
(adultsandlarvae) - 6 3 - 5 2 16(10.19)
(b) Ground beetlelarvae 1 - - - - - 1 (0.63)
5 Lepidoptera (a) Caterpillar - - 7 12 - - 19(12.10)
(b) Butterfly 3 - - - - - 3(1.91)
(c) Moth - 4 2 - - - 6(3.82)
6 Diptera Flies 1 1 1 - - - 3(1.91)
7 Hymenoptera (a) Ants 3 7 2 6 - - 18(11.45)
(b) Honeybee
(adultandlarvae) 21 10 4 - - - 35(22.29)
(c) Wasps 6 9 1 - - - 16(10.19)
(adultandlarvae)
(Totalnumberofinsectscontainedinthegutsof41 HimalayanNewtsfromApriltoOctober1996= 157)
J. Bombay Nat. Hist. Soc., 102 (2), May-Aug 2005 167
FOOD OF THE HIMALAYAN NEWT TYLOTOTRITON VERRUCOSUS
25 observation is that it also consumes its own eggs.
Therateoffoodconsumption ishighinMay,Juneand
20 July, decliningafterAugust.Thegutofthe newtisdevoidof
food materials in October. Voracious consumption of food
15 coincides with the onset of reproductive activities in June.
Apart from insects, which constitute the main food items of
PERCENTAGE
20 the newts, fragments ofplants, small pebbles and mud were
found in their guts. These are perhaps ingested incidentally.
5 The rainy season starts in May and continues up to July;
during this period the newts consume the small molluscs,
0 which abound in theirhabitat. The newts layeggsfromJune
to August.
ACKNOWLEDGEMENT
Fig. 1:QuantityofinsectsfoundinthegutsofHimalayanNewt I thank the teamofthe ICTV, an Imphal - basedcable
TV operator, who visited the Zaimeng lake for a video
gut ofthe newts collected betweenApril and September are coverage ofthe newts in July 2002, for presenting four live
predominantly insects and insect parts. An interesting newtsto me.
REFERENCES
Nair,S.M.(1996):EndangeredAnimalsofIndiaandtheirConservation. Riley, N.D. (1977): Insects in Colour. Blandford Colour Series, Link
National BookTrust, IndiaA-5 Green Park, New Delhi. House, West Street, Poole, Dorset BIHS 166.
Richards, O.W. & R.G. Davies (1977): Imm’s General Textbook of Zanetti, Adriano (1977): The World of Insects. Sampson Low
Entomology, Vol. 2 Classification and Biology. Chapman and Berkshire House, Queen Street, Maidenhead, Berkshire SL, 6
Hall Ltd., 11 New FetterLane, London. INF.
168 1 Bombay Nat. Hist. Soc., 102 (2), May-Aug 2005