@@B D9+82;7+*8 doi: 8+87788E9+82+*8 http://folia.paru.cas.cz Research Article Feeding strategies and competition between terrestrial Haemadipsa leeches (Euhirudinea: Arhynchobdellida) in Danum Valley rainforest (Borneo, Sabah) =andb !"#$3& F!!$GH!$ $G!G!!%![J- ography and taxonomy. We undertook research on two species inhabiting lowland dipterocarp forest, Haemadipsa picta K8'9' and Haemadipsa subagilis MK8'9'N!&PMN!ƽ!G G&ƽ-R=MGNG!J-[R=MN-[ GƽG!$$!RS!&!H. picta is more G!ƽ-$&!!=!J&! plant height. Haemadipsa subagilis &U!G!VG&[ G&!MNJ-H. pictaM!&![N= (ii) habitat specialisation of H. subagilis. Moreover, we provide new observations on their foraging behaviour. ectoparasites, foraging behaviour, Haemadipsidae, haematophagy, parasitism HB!->!G$- $ [ !& $ !-!!F- G!ƽ M>!!!GN &!! !GPB- $1+Z!! G ! [ $ ! ! -!HaemadipsaH81<'M brown leech species complex (former H. zeylanica sensu B9++79+8+BH%9++1NH!! latoB9+8+NP- fauna of the Oriental region has received much attention mary tropical rainforest, whereas more disturbed environ- !&KM8'9'8'*<8'*1N ments are dominated by conspicuously coloured H. picta. The tiger leech H. picta K 8'9' & G& !- coloured species, namely H. subagilis MK8'9'N gies of hematophagous leeches, have not been examined H. sumatrana MF 811*N & - G\! !& mortality and, therefore, their abundance in an ecosystem MB&8'19$!9++7N MK8'21NF&$G Many ecological aspects of the life history of haemad- simply apply this theory to ectoparasites, such as leeches, ipsid species remain unresolved, including establishing &!!!!B an average life span for each species and species habitat GG&!UM DM8'1<N G8';;N!-U$- important studies on the feeding habits of species of Hae- $ $G P- madipsa, and until now this was the only paper containing G!!G&-[ detailed data on growth after feeding and the length of time competition and niche partitioning. !&!G [ $ ! - P!GM[$ [!G!$- 38'1'3!9++*@!H!9+89N &!&P- H!&G3M9+89N$- MN ! ! -!G G ed insights into changes in leech species proportion in species of Haemadipsa&M39+89N =!"#$%&'*+-*123& !67189;;7;7<<=>-? This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 8+87788E9+82+*8 b>G!$Haemadipsa leeches AB S1 S2 P1 P2 P3 P4 P5 2 km 50 km Fig. 1. A Mj[_@$M[_@NBG!MKN=BM[_D@M[_D@N $!M8M<NMB8B9NK[V et al. M9+++N do H. picta and H. subagilis exhibit variable population BJHaemadipsa pictaK8'9' densities as a result of greater host availability on trails vs for this survey. ƽ-R=MGNG!G! `! i.e. amongst leaf litter, as well as on the foliage of plants BJMN Morning Afternoon Total Z Age category 9!!M!!!G&! session session ` species complex for the ground and H. picta for growing ;M8* 97 9< 7' 97 "$ &MB!8'<'N=&!! 87M98 8* 87 92 8* "$ a host, does the placement of the leech (forest litter vs plant 99M9' 81 88 9' 87 BG NGJ-[- *+M*2 78 8' ;+ *+ Adult R=MNG!-[ *1M7< 97 89 *; 81 Adult !R 7;M<* 9 - 9 8 Adult Total 899 18 9+* 8++ MATERIALS AND METHODS H! & H >- D@$!&"9+8;[_ G&1M8+KG!!GP MBG!NMD8NH&! stopped data collection after dusk due to very low leech activity. species were chosen for analyses, Haemadipsa picta and H. sub- @!&$$$&!<+Z agilis HU & [ ! G !- ethanol and labelled with all necessary information (i.e. collec- !MK8'9'N!G tion time, locality, the type of habitat and approximate time since $!M9++7NB&$ the last rainfall). [ ! &-- Animals were measured on the day of collection to reduce the long survey was conducted to determine localities characterised time they were kept in ethanol to only a few hours. Leeches were G$!M&!8+!!- !$[ ! & G$N # $ & ! !MB&8'19N [$!M8M<N!!&! Millimetre graph paper was used for morphometrics. Total body MB8B9U8++9 plots). Two length was measured from the margin of an anterior sucker to the localities in the primary rainforest and one in the secondary rain- !$ &U$EM9 $GJM!9++'NUJ *B8=D8N[_ were distinguished for H. picta MHG 8 N - G![&!- $&![&!G& >!GM`&G statistical analyses. 8'''NB!- [ƽ!GG&!G& monly composed of rattan palms (mainly of the genera Calamus, &-&`S_H!!GMƽ-N Daemonorops and Korthalsia="!8'';N=! ! M < ! is uneven and with dominant Koompassia excelsaMDGN- 89 ! ! N & [U $&&M'M89K*M;KN factors and the number of individuals gathered during a session as !!M[U the dependent variable. The time after last rainfall, which can be !8!Nƽ-M!! treated as an estimator of humidity (higher shortly after rainfall 8!8<!N!!$ and lower during longer periods without rain, respectively), was localities. One collecting session lasted approximately one and !G&ƽ! !![![!!& !!M39+89NHU&!! D9+82;7+*8 92 8+87788E9+82+*8 b>G!$Haemadipsa leeches A 24 B 7 22 6 20 18 5 16 14 4 12 10 3 8 2 6 4 1 2 0 0 ç ç Fig. 2. $G$M8++9 plot) occurring in the particular type of habitat. A – Haemadipsa picta K8'9'=B – H. subagilis MK8'9'NH!'<Z[$ 31 H&-&`S_$[- 30 MD{281{++9N!GH. pic- 9 29 taG&M$G$E8++ : 28 `t{8;</8'Nƽ-M`o{'9/81N! %!! 27 `!GH. subagilis were found 26 MD{987{+82=`t{9;/+<`o{7+/8+= 25 D9G!N! 24 -[M{+21+91$N 23 S-& `S_ [ ƽ $ 22 body length (L) of H. picta collected during the morning Mj{91+/8+NMj{9*;/8*= 21 D{;1'{++8=D*N&!!M 20 !!J&HG8N! !3-V$- ferences in the case of H. subagilisMF{+<8{+71N Fig. 3. An average body length (mm) of Haemadipsa picta K8'9'$!MKN- [ $ G& MNH!'<Z[$ ambush (i.e. the height from which leeches fall onto their hosts or simply attach to them) and body size was discov- ered for H. pictaM-{+1*~+++8NH!G[$ individuals of H. picta of distinct body sizes preferred hunting describing these data points had a logarithmic character ƽ & -& `S_ MD7N!&P& with the time of a day (morning vsN![U !{*+;19&8+MUN-9929<9`!- independent factor and the body length as the dependent variable. lation was detected for H. subagilisM-{-++1{+<;N V3-VG!H. subagilis due to the considerably smaller sample size. To establish if there DISCUSSION &[G&J!! !!&!!!- !"#$#% BR!&H!G[$ "& P-&!G! &&! !G&!$GB- !G P ƽ $ MB rors are presented after ± mark. 8'';V9++; 9++1NB!!!- RESULTS madipsid genera: whereas species of Haemadipsa occur in 9+<$Haemadipsa picta <7- $!!G&Mj9+88N dividuals of H. subagilis&K!'+Z !!$G$1++MK H. subagilis were found on the ground, which prevented 8'9'NG!Tritetrab- direct testing of the second hypothesis for this species. Two della K 8'*1 G specimens of H. picta and one individual of H. subagilis G$89++M39+8*` were excluded from the analyses due to evident enlarge- 9+8;NF&$!$G&!! ment of the body after feeding. members of the same genus remains unclear. D9+82;7+*8 *2 8+87788E9+82+*8 b>G!$Haemadipsa leeches 50 A 40 30 20 10 B 0 0 20 40 60 80 100 120 140 160 180 200 220 Fig. 4. The dispersion plot depicting the correlation between the length and preferred altitude of attack of Haemadipsa pic- ta K8'9'H!G-[!$& ! & P ! $ {*+;19&8+MUN-9929<9 The present study shows that H. picta exhibits oppor- tunistic behaviour and agglomerates in the vicinity of ani- mal trails used mainly by mammals such as humans, beard- P&!! Fig. 5. Typical postures of haemadipsid leeches on the example of increase in hunt success ratio. The average number of col- Haemadipsa pictaK8'9'AM=B – in at- tack position. Photo ©Jj&&! $&$!!ƽ-!G is worth mentioning that host preferences for both species & G B! M9+8<N [_N&!!G- that mammals and amphibians are hosts of Haemadipsa itat, or temporal variation would be observed. and TritetrabdellaM!9+89G summary of records of species of Haemadipsa spp. para- '#%"& sitising amphibians). Generally, H. picta exhibits visible vertical intraspecif- j@!M9+8+N- ic niche partitioning. We demonstrated strong correlation nant hosts of leeches of Haemadipsa and our results sug- between the size of H. picta and the height from which it gest that these leeches can be choosy in selecting particular !H!!-! !PJ&[ and is likely shaped by a compromise between (i) energy ƽ!GH. subagilis across sam- expenditure associated with foliage climbing, and (ii) the pled habitats. A considerably lower sample size could have !R!G \!!!$G- !&$[G $![ individuals to crawl slightly higher above the surround- could be discovered when more leeches are collected and $ M 9+ U measured. ;+N!!! [$!JH. picta G!U!!$- means that relatively larger specimens (from the third size dividuals do not have to climb much higher, because there &ƽQGR!N!- !!&!! !&!%$M[&J !$!!!&!U9 classes) exhibited similar activity throughout the day. Giv- M!G&MG!82N !!&!MB& !$%H. subagilis were collected from 8'18N!$!- !G[ erences connected with aging, a factor previously report- to the ground, most probably as other cryptically coloured G[ members of the genus from the brown leech species com- G&M!9+8;NH! plex (i.e. former subspecies of H. zeylanica KP-H- we hypothesise that a similar mechanism could alleviate 8192=B9+8+N`$- [&!H. picta ertheless, six individuals of H. subagilisM88ZN& contrast, no such phenomenon was detected for H. subagi- on foliage. There are two possible explanations for this: lis.