Zooplankton secondary production models in cultures of Daphnia magna: A comparison study

ZOOPLANKTON SECONDARY PRODUCTION MODELS IN CULTURES OF Daphnia magna: A COMPARISON STUDY M. Gómez1, I. Ma ínez1, I. Mayo1, J.M. Mo ales1 & T.T. Packa d1 1 Labo a o y o Biological Oceanog aphy. Depa men o Biology. Uni e si y o Las Palmas de G an Cana ia. Cana y Islands, SPAIN E-mail: [email protected] INTRODUCTION RESULTS Seconda y p oduc ion is he e o ophic g ow h, he a e o biomass inc ease pe ime in zooplank on o ben hic me azoans. I e lec s he ne balance be ween me abolic gains in biomass and he in eg al o all me abolic losses. Then, modeling seconda y p oduc ion a es in he zooplank on is essen ial o popula ion ecology s udies, ye assessing hese a es is di icul , indi ec , and poo ly known o he gene al ecology communi y. He e we es i e seconda y p oduc ion models in cul u es o Daphnia magna (Hun ley and López, 1992; Hi s and Sheade , 1997; Hi s and Lampi , 1998; S ockwell and Johansson, 1997; Shu e and Ing, 1997). Mo he cul u e (20L) Phy oplank on cul u e (Scenedesmus sp, Ankis odesmus sp.) Yeas cul u e (Saccha omyces ce e isiae ) Co n lou cul u e (come cial) MATERIAL AND METHODS Ha es Size measu emen s F eeze (-20ºC) Pa ame e s: * D y mass * G ow h a es *Condi ion ac o [ CF = (a·W)/L3 ] Seawa e models Hun ley and López(1992) g = 0.0445·e0.111T Hi s and Sheade (1997) g=0.0732·100.0246T/Wc0.2962 Hi s and Lampi (1998) g=0.0723·100.0208T/Wc0.3221 F eshwa e models Shu e and Ing(1997) P=10(α+βT)·B S ockwell and Johansson(1997) P=10(alog10M+b)·CF·M·N Di e en cul u es o D. magna we e g own on phy oplank on, bake ’s yeas o co n lou a 18-21ºC. G ow h a es we e calcula ed om ime cou se o size (Fig.1) and d y mass (Fig.2). Wmax (µg) = 153 Wmax (µg) = 110 Wmax (µg) = 150 gglobal(d-1) = 0.19±0.02 CF = 5.78 gglobal(d-1) = 0.295±0.04 CF = 1.19 gglobal(d-1) = 0.111 ± 0.006 CF = 4.51 Fig1. Daphnia magna g ow h as unc ion o size and d y mass, ed on h ee di e en ypes o ood. Indica ing he measu ed alues o global g ow h a e (gglobal), maximum weigh (Wmax) and condi ions ac o (CF) o each ype o ood. O e es ima ed alues Simila alues Unde es ima ed alues Fig4. Modelled e sus measu ed g ow h a es in D. magna ed h ee di e en oods. The line in all h ee panels ep esen s a one- o-one co espondence. The key iden i ies he models used. Fig3. Measu ed daily a es o seconda y p oduc ion in Daphnia magna g ow h on h ee di e en ypes o ood Conclusion 1: Al hough he highes global g ow h a es we e ob ained wi h yeas (0.295 d-1), he highes alues o he condi ion ac o (5.778) and seconda y p oduc ion (643 g d y mass· d-1)as well as he maximum weigh we e ound in Daphnia ed on phy oplank on (Fig1 and Table 2). A mix u e yeas and phy oplank on should be he op imal ood o cul u ing Daphnia magna. Conclusion 2: The Hun ley and López (1992) model o e es ima es seconda y p oduc ion, he Hi s and Sheade (1997) and he Hi s and Lampi (1998) models unde es ima ed hem. The bes seconda y p oduc ion calcula ion was ound using he S ockwell and Johansson (1997) model (Fig4 and Table 3). This conclusion is also ex apola ed o he obse ed daily g ow h a es (Table 1). Conclusion 3: On a u ili a ian basis, because size is such a good index o biomass and so easy o measu e, we ecommend moni o ing i , ins ead o d y-mass, in u u e g ow h- a e s udies. Mon agnes e al. (2010) also ecommend size as a p oxy o d y-mass in Oxy his ma ina. REFERENCES Hi s , A.G. and M. Sheade , 1997. A e in si u weigh -speci ic g ow h a es body-size independen in ma ine plank onic copepods? A e-analysis o he global syn heses and a new empi ical model. Ma ine Ecology P og ess Se ies 154:155-165 Hi s , A.G. and R.S. Lampi , 1998. Towa ds a global model o in si u weigh -speci ic g ow h in ma ine plank onic copepods. Ma ine Biology 132:247-257 Hun ley, M.E. and M.D.G López, 1992. Tempe a u e-dependenden p oduc ion o ma ine copepods: a global syn hesis. Ame ican Na u alis ,140:201-242 Lo eg o e, T., 1966. The de e mina ion o he d y weigh o plank on and he e ec o a ious ac o s on he alues ob ained. In: Some com epo a y s udies in ma ine science. (H. Ba nes ed.). Geo ge Allen and Unwin LTD. London. pp 429-467. Shu e , B.J. and K.K. Ing, 1997. Fac o s a ec ing he p oduc ion o zooplank on in lakes. Canadian Jou nal o Fishe ies and Aqua ic Sciences 54:359-377 S ockwell, J.D. and O.E. Johansson, 1997. Tempe a u e-dependen allome ic models o es ima e zooplank on p oduc ion in empe a e eshwa e lakes. Canadian Jou nal o Fishe ies and Aqua ic Sciences 54:2350-2360 Mon agnes, D.J.S., C.D. Lowe, L. Ma in, P. Wa s, N. Downes-Te ma i, Z. Yang, E.C. Robe s & K. Da idson, 2010.Oxy his ma ina g ow h, sex and ep oduc ion. Jou nal o Plank on Resea ch, doi: 10.1093/plank / bq111 Table 3. Rela ionship be ween p edic ed and measu ed da es o seconda y p oduc ion Kind o ood Hun ley and López (1992) Hi s and Sheade (1997) Hi s and Lampi (1998) S ockwell and Johansson (1997) Shu e and Ing (1997) Phy oplank on 14.99x – 766.73 2 = 0.48 (slope = 14.99) 1.72x - 82.51 2 = 0.57 (slope = 1.72) 1.24x – 59.26 2 = 0.58 (slope =1.24) 0.88x + 14.90 2 = 0.76 (slope = 0.88) 5.23x - 268.41 2 = 0.48 (slope = 5.23) Yeas 4.30x – 104.65 2 = 0.64 (slope = 4.30) 0.61x – 12.07 2 = 0.71 (slope = 0.61) 0.32x + 0.14 2 = 0.64 (slope = 0.32) 1.09x + 0.99 2 = 0.78 (slope = 1.09) 1.50x – 36.69 2 = 0.64 (slope = 1.50) Co n lou 24.6x – 733.89 2 = 0.57 (slope = 24.6) 3.16x – 88.35 2 = 0.55 (slope = 3.16) 2.31x – 64.25 2 = 0.54 (slope = 2.31) 2.31x – 42.56 2 = 0.48 (slope = 2.31) 8.76x – 261.67 2 = 0.57 (slope = 8.76) Table 2. Seconda y p oduc ion alues ob ained wi h se e al models in µg d y mass·d-1 Kind o ood Measu ed da es Hun ley and López (1992) Hi s and Sheade (1997) Hi s and Lampi (1998) S ockwell and Johansson (1997) Shu e and Ing (1997) Phy oplank on 643 1979 283 208 719 683 Yeas 452 1000 169 127 502 349 Co n lou 350 1286 224 169 386 454 Table 1. Daily g ow h a es (d-1) ob ained wi h se e al models Kind o ood Measu ed da es Hun ley and López (1992) Hi s and Sheade (1997) Hi s and Lampi (1998) S ockwell and Johansson (1997) Shu e and Ing (1997) Phy oplank on 0.221 ± 0.162 (n = 10) 0.484 ± 0.067 (n = 10) 0.076 ± 0.022 (n = 10) 0.056 ± 0.017 (n = 10) 0.248 ± 0.189 (n = 10) 0.166 ± 0.021 (n = 10) Yeas 0.332 ± 0.262 (n = 9) 0.419 ± 0.030 (n = 9) 0.087 ± 0.031 (n = 9) 0.067 ± 0.026 (n = 9) 0.372 ± 0.322 (n = 9) 0.146 ± 0.009 (n = 9) Co n lou 0.113 ± 0.051 (n = 10) 0.362 ± 0.050 (n = 10) 0.065 ± 0.012 (n = 10) 0.049 ± 0.009 (n = 10) 0.120 ± 0.041 (n = 10) 0.128 ± 0.016 (n = 10) Bo h he g ow h (Fig.2) and he seconda y p oduc ion (Fig.3) displayed a cohe en pa e n du ing he i s 12 days: Daily g ow h a es dec eased con inuously wi h he s eepes decline in he yeas (Fig. 2) Daily seconda y p oduc ion o he cul u e ed on phy oplank on and co n lou inc eased sligh ly, whe eas in he cul u e ed on yeas he inc ease in he i s 5 days is g ea e (Fig.3). Fig2. E olu ion o daily g ow h a es, g(days-1), o Daphnia magna on h ee di e en ypes o ood