First record of the invasive Arctodiaptomus dorsalis (Marsh, 1907) (Copepoda:Calanoida:Diaptomidae) in Lake Lanao (Mindanao Island, Philippines)

Abstract

Arctodiaptomus dorsalis, originally described to be distributed within the Americas, has been documented to occupy a significant number of freshwater lakes in the Philippines. This paper reports the first record of A. dorsalis in Lake Lanao, an ancient lake located in the island of Mindanao. Based on its very high abundance, and positive correlation between the total body length of females with lake dissolved nitrates, phosphates and chlorophyll a concentration, A. dorsalis has clearly established itself in the lake ecosystem and has benefitted in the steady increase in the lake's nutrient load. Lake Lanao's endemic Tropodiaptomus gigantoviger may be considered as another calanoid species to be displaced by A. dorsalis given that a thorough examination of plankton samples collected from Lake Lanao have not yielded individuals of T. gigantoviger.

Philippine Seven Tropical Maar Lakes are Ideal Habitats for the Invasive Arctodiaptomus dorsalis Marsh, 1907 (Copepoda: Calanoida)

“…All temperature readings obtained during the three months of sampling fall well within the optimal temperature range of A. dorsalis (Figure 3), supporting the positive correlation we were able to observe for our samples. et al 2012;Metillo et al 2014;Rizo et al 2015;Lopez et al 2017). Various literature has also established that this invasive calanoid has high propensity towards eutrophic waters (Elmore 1983;Reid 2007;Tordesillas et al 2018;de Leon et al 2020), which are the natural state of the country's lakes (Woltereck et al 1941).…”

“…However, the scale of its invasion was only realized a decade ago, when an attempt to update the country's plankton zoogeography discovered its presence in 18 out of 27 investigated lakes (Papa et al 2012). Since then, this number has increased with studies reporting its presence in new localities (Metillo et al 2014;Rizo et al 2015;Lopez et al 2017). The successful entry and proliferation of A. dorsalis in Philippine inland waters can be attributed to the natural eutrophic state of our lakes (Woltereck et al 1941) and the high reliance of the country's communities on aquaculture (Papa and Briones 2014).…”