A study originally intended to update the systematics and zoogeography of calanoid copepods in Philippine lakes has led to the discovery of an invasion by the Neotropical Arctodiaptomus dorsalis. It now occurs in 18 out of 27 lakes in the archipelago. Only four of the 12 previously recorded native and endemic calanoids have been encountered in the lakes, which may indicate that most have been displaced by A. dorsalis, although a general deterioration of water quality by fish culture may also have contributed to a suppression of the local fauna. Undescribed species may have been affected as well. A. dorsalis was first reported in the Philippines from Laguna de Bay in 1991, where it was said to have been introduced via ship drinking water reserves, but co-introduction with tilapia is more probable. Intensive aquaculture practices during the past 20 years have aided its dispersal to other areas and have provided environmental conditions that favor its survival. The rapid spread of A. dorsalis, paralleled by a loss of calanoid diversity in the Philippines, may repeat itself if this opportunistic species succeeds in spreading to mainland Asia

A massive invasion of the Neotropical calanoid copepod Arctodiaptomus dorsalis (Marsh, 1907) has been taking place in the Philippines since at least 1993. This copepod’s fecundity is known to depend on food concentration, increasing temperature appears to have detrimental effects on its hatching success and survivorship, but parameters that are truly predictive of the successful integration and propagation of this species in particular bodies of water have not yet been identified. We conducted a spatial analysis of morphometric features and reproductive capacity, the latter proxied by clutch size (CS), of different populations of A. dorsalis inhabiting 11 tropical lakes in the Philippines. Correlations between either morphometry or CS and selected water quality parameters were investigated based on collections and measurements made from December 2018 to April 2019. Means of morphometric measurements differed significantly (P < 0.001) among the populations of A. dorsalis in all lakes. Total length (TL) of adult males, TL of non-ovigerous adult females, and CS of ovigerous females all showed significant (P < 0.001) inverse correlations with lake depth, accounting for about 30% of the observed variability among lakes (r = –0.55, –0.55, and –0.58, respectively). Shallow lakes, which are more homogenous in terms of nutrient distribution throughout the water column, thus provide a more suitable habitat than deep lakes for A. dorsalis and provides a partial explanation of the widespread occurrence and abundance of the species in the shallower, more eutrophic lakes in the Philippines.

Arctodiaptomus dorsalis is an invasive calanoid copepod from America, and is now found in 23 out of 32 lakes and rivers in the Philippines. Live specimens of A. dorsalis were collected from Lake Taal and cultured in the laboratory. The specimens were reared under three different temperatures (25°C, 30°C, and 35°C) with the same food and light conditions, i.e. ~10 5 cells mL −1 of Chlamydomonas reinhardtii and 12L:12D at ~60 lx, respectively. Post-embryonic development times from hatching to adult decreased from 31.5 d to 18.3 d as the temperature increased, while those during naupliar stages were quite similar, i.e. 4.4, 2.8 and 2.3 d at 25, 30 and 35°C, respectively. The naupliar durations were substantially shorter than the copepodid stages. Clutch sizes were almost the same, 8.7-9.2 eggs clutch −1 , among all temperatures tested, while hatching success decreased from 85.9% at 25°C to 24.2% at 35°C. Overall survival rates from hatching to adult decreased as well from 67% at 25°C to 23% at 35°C. This is the first successful attempt to culture A. dorsalis collected from a freshwater lake in the Philippines.

No 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.

Introduction: Quality-of-life (QOL) is paramount in clinical decision-making in the management of prostate cancer patients. The expanded prostate index composite (EPIC) is a widely used and well-validated QOL tool that allows for the evaluation of bowel, urinary, sexual, and hormonal domains. A Filipino translation was previously lacking. We describe the development and pilot testing of the Filipino translation of the EPIC (EPIC-F). Methodology:The EPIC-32 was translated into Filipino using iterative forward and backward procedures with checks for semantic congruency. The translation was then evaluated by an expert panel consisting of a prostate cancer survivor and pertinent health professionals. A focused group discussion (FGD) was conducted to explore sources of difficulty of use to guide improvement. Results:The linguistically validated translation was evaluated to have cultural relevancy, adequacy, and representativeness by the expert panel, and to have good understandability and answerability by a representative pilot cohort of prostate cancer patients. Seven unsatisfactory items were identified, all pertaining to the sexual domain, and required minimal revision on review during the FGD. Conclusion:The EPIC-F is a linguistically and culturally validated version of the EPIC 32, with good understandability and answerability, permitting clinical use. Its psychometric properties need to be determined to define its utility in clinical research.

The presence of the invasive calanoid copepod Arctodiaptomus dorsalis in Philippine inland waters has been reported in numerous studies. Attempts to understand how it effectively proliferated in the country’s freshwaters have shown its preference towards shallow and productive waters – a feature shared by most lakes in the Philippines. In this study, we compared the body size and reproductive capacity – proxied by clutch size (CS) – of ovigerous female A. dorsalis obtained from established populations in the seven maar lakes (SML) of San Pablo, Laguna, Philippines. These measurements were also correlated with selected water quality parameters. Collection of ovigerous A. dorsalis and water quality parameters were conducted on a 3-mo sampling period during the southwest monsoon season in 2016. Statistical analysis shows that there exists a significant difference between the prosome length (PL) and CS of A. dorsalis from the seven lakes (p < 0.001), with the shallowest and most productive lake containing the most fecund population. Additionally, all water quality parameters showed a positive correlation with the PL and CS of ovigerous A. dorsalis from the SML (p < 0.01). This shows that the SML provides favorable conditions for the propagation of A. dorsalis, making it a model for in situ investigation of this invasive species’ ecology; the first step in incorporating zooplankton ecology as a tool for the development of lake management systems.

No abstract