THE EFFECT OF DIFFERENT STIMULI ON MEGRE (rgyrosomus regius) FEEDING EHVIOUR. Ionnis E. Ppdkis, Nikos Ppndroulkis, lkioni Sfendourki, Veronic Cmporesi 3, Mnolis Vsilkis, Constntinos C. Mylons Institute of Mrine iology, iotechnology nd quculture, Hellenic Center for Mrine Reserch, quls, Thlssokosmos, P.O.ox, 4, Irklion Crete, 7003. Emil: ppd@hcmr.gr iology Deprtment, University of Crete, P.O. ox 08 Herklion 74 09 Crete, Greece. 3 University of ologn, Diprmento Di Scienze Mediche Veterinrie. Vi Tolr di Sopr, 50-40064 Co-funded y the Seventh Frmework Progrmme of the Europen Union
Introduction The study exmines the effect of different stimuli on feeding ehvior. In nture megre inhit res close to the se ottom. Relted to: Mouth position. Slow swimming ctivity. Visul system (D vision). Swimming re In frming cges fish express the sme ehviorl pttern inhiting the lower section of the cge. Modifiction y: Light conditions. vilility of food.
Introduction in cges is prolemtic ecuse the frmers do not see the fish during the feeding procedure. Resulting in: Loss of food. High Food Conversion Rtios (FCR). Incresed production costs. Swimming re
Introduction Ojectives: Develop feeding method for cge frming, ttrcting the popultion to specific feeding re, where mngement will e more effective. re stimuli The methodology is sed on three steps:. Stimulus for the feeding time. ttrction to the feeding re Swimming re 3. ctul
Introduction The stimuli used rely on vision nd mechnoreception. Light (fding) ir ules Sensory system Vision Mechnoreception nd vision Experiment durtion of 60 dys. The effect of stimuli on feeding ehvior of megre in nturl light conditions.
Cmer Mterils nd methods Cmer Cmer Feeder Feeder Feeder Light light in the wter column. Experimentl conditions: ) 5 m 3 outdoor tnks ) Initil fish weight (636 ± 56g) c) 0 individuls in ech tnk ules ir ules in the wter column. Control without stimuli.
Mterils nd methods Schemtic representtion of recording periods during the dy nd nlysis of stimuli Dy length 07:30 :30 8:30 8:30 fter No efore 4:30 fter No efore 0:30 fter No efore time Recording periods 5 minutes video 5 minutes video stimuli + feeding 0 Time (sec) 5 minutes video 0 40 45 48 3 4 5 durtion
nlysis with Kinove nd Imge j C 6 5 D E F 4 3 Mterils nd methods nlyzed 70 pictures for ech 5 minute video t different times per dy. The tnk ws divided in 6 res. The coordintes from the corners from ech squre were mrked. = (X, Y), = (X, Y)..etc. Ech fish coordintes were extrcted using imge J: Fn (Xn,Yn) Clcultions re numer (X=0, Y=0) G H I Stimulus re J K L IF (X,Y) were etween H I L K IF (X,Y) were etween IF (X,Y) were etween IF (X,Y) were etween IF (X,Y) were etween G H K J E F I H 3 D E H G 4 C F E 5 Plce of feeder nd stimuli IF (X,Y) were etween E D 6
nlysis with Imge j Mterils nd methods Numer of re Numer of fish in Ech re % distriution of the fish in ech re (X=0, Y=0) C D E F G 6 6 5 4 3 4 4 4 4 Plce of feeder nd stimuli 6 H J K L 5 Plce of hed of the fish 5 3 Stimulus re I 3 4 5 6 0 4 0 % 0 % 0 % 40 % 0 % 0 % The sttistic ws performed using the percentges fter their trnsformtion in rcsine squre root vlues
% distriution of the fish Results- periods without stimuli (3) 0:30 (4) :30 (noon) (5) 5:30 Light conditions ffect the ehvior of megre. Megre during the morning nd the fternoon (low light intensity) moved continully nd were distriuted in ll the res of the tnk. () 07:30 (morning) () 8:30 (fternoon) During the other periods of the dy (high light intensity), they prefer to inhit the dusky res of the tnk. (NOV, Duncn test, P<0.05) re of the tnk Uppercse letters = differences etween res Lowercse = differences etween conditions for ech re Time (hours)
% distriution of the fish Results t the morning (07:30) Sun light intensity >,000 lux ) efore stimulus Light stimulus E re The stimulus of light nd Control D C Light ir ules c ttrcted the ir c experimentl popultion C to the feeding re c during its implementtion. ir ules stimulus D C ) Stimulus Control Light ir re re of the tnk (NOV, Duncn test, P<0.05) Uppercse letters = differences etween res Lowercse = differences etween conditions for ech re
% distriution of the fish Sun light intensity < 30,000 lux Light stimulus ir ules stimulus stimulus Results t the noon (:30) The stimulus of ir ules ) efore ttrcted stimulus D the experimentl popultion Control to the Light feeding re during its ir implementtion, more C thn the light. c c The sun light intensity overlpped the light re stimulus intensity nd the stimulus ecme not visile. re re of the tnk (NOV, Duncn test, P<0.05) Uppercse letters = differences etween res Lowercse = differences etween conditions for ech re C c C ) Stimulus Control Light ir
% distriution of the fish Sun light intensity >,000 lux Light stimulus Results t the fternoon (8:30) D ) efore stimulus The stimulus of light nd ir ules c C ttrcted the experimentl popultion to the feeding re during their implementtion. ir ules stimulus stimulus D C ) Stimulus re of the tnk (NOV, Duncn test, P<0.05) Uppercse letters = differences etween res Lowercse = differences etween conditions for ech re
Conclusions Light conditions ffect the ehvior of megre. Megre without direct sunlight (morning nd fternoon) present higher motility thn during direct exposure (noon). During noon (direct sun light exposure) fish prefer to inhit dusky res of the tnk. Megre is le to lern nd rememer specific stimuli tht re ssocited with feeding. Megre responded to ir ules very quickly (from the second dy of ppliction). Megre responded to the light stimulus only without direct sunlight. Inility to see the stimulus? oth ir ules nd light or comintions of them cn e used in n industril setting, s they cn e mnufctured, implemented nd mnged esily with existing technologies in se cges.
Thnk you!!! THE EFFECT OF DIFFERENT STIMULI ON MEGRE (rgyrosomus regius) FEEDING EHVIOUR. Ionnis E. Ppdkis (ppd@hcmr.gr) Nikos Ppndroulkis lkioni Sfendourkis Veronic Cmporesi 3 Mnolis Vsilkis Constntinos C. Mylons Institute of Mrine iology, iotechnology nd quculture, Hellenic Center for Mrine Reserch, quls, Thlssokosmos, P.O.ox, 4, Irklion Crete, 7003. iology Deprtment, University of Crete, P.O. ox 08 Herklion 74 09 Crete, Greece. 3 University of ologn, Diprmento Di Scienze Mediche Veterinrie. Vi Tolr di Sopr, 50-40064 Co-funded y the Seventh Frmework Progrmme of the Europen Union