| dc.description.abstract | People and home industries activities along Ciliwung river impact to water quality. Pollutant in body of river will impact to water quality and organisms, included water strider. Water striders (Gerridae: Hemiptera) are semiaquatic insect. Gerrids, Ptilomera Amyot and Serville is easy to know, because have rather big body and have sexual dimorfism. A bigger body male than female is unusual in gerrids. Some species of water striders were used as water bioindicator. Gerris spinolae is effective bioindicators for monitoring pollution in some tropical ponds under anthropogenic stress, whereas G. argentatus, G. odontogaster, G. lateralis, dan G. thoracicus used as bioindicator of heavy metals. The purpose of this research was to study the abundance of P. dromas in Ciliwung river related to water quality. Five stations in upper Ciliwung river were used i.e, Cilember, Cijulang, Gadog, Katulampa, and Sempur stations. Abundance of water striders were observed by census method. Water striders were count directly along the edge of the river on each station. Observations were conducted four times each day, at 07.00-11.00 am. Abundance of water striders each stations was observed five times in November, December 2013, April, and May 2014. Measurement of environmental parameters was conducted at each station with five replicates, i.e. water temperature, air temperature, pH, and water flow. Water sampling was conducted by using a sampel bottle 1 L, then put in an ice box 4oC. Water samples were analyzed in the Laboratory PROLING Faculty of Fisheries and Marine Science Bogor Agricultural University, consist of biological oxygen demand (BOD), dissolved oxygen (DO), CO2 free, total Nitrogen (N), hardness, and total suspended solid (TSS). A normal data of environmental parameters were analyzed by One-Way ANOVA followed by Tukey test. Abundance of adult, nymph and total P. dromas were analyzed by Kruskal Wallis. Abundances of water strider related with environmental parameters were analyzed by GLM using a Poisson distribution, then followed by GLM using negative binomial distribution. Analyses were performed using program R 3.0.0. Results showed that three species of water striders were found in Ciliwung river, i.e. Ptilomera dromas Breddin, Limnogonus nitidus and Tenagogonus robustus. Gerrids, P. dromas was found in Ciliwung river in the fast current, while L. nitidus and T. robustus was found in slow current and tends to stagnant. In the Sempur station, both water strider species were found, i.e. L. nitidus and T. robustus in a puddle located on the edge of the river. The highest abundance of adult P. dromas was found in Katulampa (78.8 individuls), followed by Gadog (63.4 individuals), Cilember (41.0 individuals), and Cijulang (16.8 individuals) respectively. Cilember station has highest abundance of nymph of P. dromas (178.2 individuals), followed by Gadog (158.4 individuals), Katulampa (133.4 individuals), and Cijulang (80.2 individuals). The average of abundance of total P. dromas (adult and nymph) in Gadog station was highest (221.8 individuals), followed by Cilember (219.2 individuals), Katulampa (212.2 individuals), and Cijulang (97.0 individuals). P. dromas didn’t found in Sempur station. The ANOVA analysis showed that significant differences in water temperature (p=0.000), air temperature (p=0.000) dan pH (p=0.029) in each stations. The Tukey tests revealed significant differences in the water temperature between Katulampa-Cilember stations (p=0.020), Sempur-Cilember stations (p=0.000), Sempur-Cijulang stations (p=0.000), and Cilember-Gadog stations (p=0.030). Significant differences was also shown by air temperature between Katulampa-Cilember stations (p=0.000) and Sempur-Cilember stations (p=0.004). Water pH also showed a significant difference between Gadog-Cilember stations (p=0.010). Based on GLM negative binomial analysis, water pH and hardness correlated positively (p=0.016 and p=0.022), while water temperature, air temperature, water flow, DO, and TSS correlated negatively with abundance of adult P.dromas (p=0.006, p=0.000, p=0.046, dan p=0.021). Water pH and hardness also correlated positively with abundance of nymph P. dromas (p=0.000 and p=0.000). Water temperature, DO, and TSS correlated negatively with abundance of nymp P.dromas (p=0.002, p=0.001, and p=0.000). Water pH and hardness also correlated positively with abundance of total P. dromas (adult and nymph) (p=0.000 and p=0.000). Water temperature, water flow, DO, and TSS correlated negatively with abundance of total P. dromas (p=0.000, p=0.000, p=0.000 and p=0.000). In Ciliwung river, P. dromas was found from Katulampa station toward upper river. Average abundance of P. dromas was highest in Gadog station, folowed by Cilember, Katulampa, and Cijulang station. P. dromas didn’t found in Sempur station may be related with higher proportion of TSS. Gerrids, P. dromas can be used as bioindicator on the the waters because its existence in the waters that is not polluted. | id |
