| Title |
Survival, Reproduction, and Life History Traits Evaluation of Heterocephalobellus sp. and Cephalobus sp. from an Artisanal and Small-scale Gold Mine Site, Davao de Oro, Philippines as Bioindicators of Heavy Metal Contamination |
|
Authors |
Alissa Jane S. Mondejar, Florifern Paglinawan, Carlito Baltazar Tabelin, Maricar Aguilos, Rustum Aguilos, Einstine M. Opiso, Joey Genevieve T. Martinez, Ephrime B. Metillo, Nanette Hope N. Sumaya, and Mylah Villacorte-Tabelin |
|
Publication date |
2023/12 |
|
Journal |
Philippine Journal of Science |
| Volume |
152 |
| Issue |
6A |
| Pages |
2213芒聙联2228. |
| Publisher |
Department of Science and Technology |
| Abstract |
Mining is notorious for contaminating the environment with heavy metals, disrupting the
activities of soil fauna such as nematodes, and causing changes in the functions of organisms
in the soil ecosystem. This study investigated the survival, reproduction, and typical life
history traits (LHTs) of free-living nematodes collected from an artisanal and small-scale gold
mine (ASGM) site, including how heavy metals influenced these parameters. Morphological
and molecular analyses identified Heterocephalobellus sp. and Cephalobus sp. (Rhabditida:
Cephalobidae) from the soil, which were cultured in a bacteriological agar to assess their LHT
using the hanging drop technique. These cultured nematodes were then exposed to different
temperatures (20, 25, and 30 脗掳C) to determine the optimum conditions for their survival and
reproduction. Cultured nematodes were also exposed to copper (Cu), lead (Pb), and zinc (Zn)
to elucidate the effects of these heavy metals on the nematode芒聙聶s survival, reproduction, and
LHT. Our results suggest that the ideal temperature for survival with a high reproduction
rate for both species was at 25 脗掳C. Exposure to heavy metals led to decreased survival and
reproduction at 25 and 30 脗掳C in both nematodes. In contrast, these nematodes survived longer
at 20 脗掳C with delayed reproductive maturity. At 25 脗掳C, the LHT of Heterocephalobellus sp. showed a shorter population generation time with a decreased number of offspring. Although
a shorter population generation time was also observed in Cephalobus sp., more offspring were
produced when exposed to heavy metals. Altogether, these results suggest that when exposed
to heavy metals, Heterocephalobellus sp. and Cephalobus sp. led to changes in their survival
and reproduction. To the best of our knowledge, this is the first report evaluating the survival,
reproduction, and LHTs of Heterocephalobellus sp. and Cephalobus sp. in the Philippines and
how these parameters are affected by heavy metals ubiquitous in mine sites. |
| Index terms / Keywords |
artisanal and small-scale gold mine (ASGM), egg production, hanging drop method, heavy metals, life history trait, nematode(s), reproduction rate |
| URL |
|
Mindanao State
University - Iligan Institute of Technology