PMID: 41894Oct 1, 1979

The longevity and hatchability of Philophthalmus megalurus and P. gralli miracidia in different environmental conditions

The Journal of Parasitology
P M NollenD E Snyder


The effects of salinity, pH, and temperature on the longevity and hatchability of miracidia of Philophthalmus megalurus and P. gralli were determined. Miracidia of both species are able to hatch and survive at saline concentrations much above physiological levels, although these processes are reduced in 2.0--2.4% saline and completely inhibited at 2.6%. The greatest hatching rates for both species were found near neutrality (pH 6--8) but some miracidia hatched at the extreme pH levels of 3 and 12. Philophthalmus megalurus miracidia exhibited longer half-lives under acid conditions (pH 2--6) than P. gralli miracidia; conversely, P. gralli miracidia showed longer half-lives in alkaline conditions (pH 8--11). Hatching and longevity were much greater below room temperature (5--20 C) than above (30--50 C) for miracidia of both species. Temperatures above 50 C proved lethal for eyefluke eggs. Except in acid pH, P. gralli miracidia showed longer half-lives than miracidia of P. megalurus. Comparison to studies on schistosomes revealed that the inhibitory effects of physiological saline and host body temperature on the hatching process of schistosome eggs does not occur in these 2 species of eyeflukes.

Related Concepts

Sodium Chloride, (24)NaCl
Hydrogen-Ion Concentration
Genus Megalurus

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Sexual Dimorphism in Neurodegeneration

There exist sex differences in neurodevelopmental and neurodegenerative disorders. For instance, multiple sclerosis is more common in women, whereas Parkinson’s disease is more common in men. Here is the latest research on sexual dimorphism in neurodegeneration

HLA Genetic Variation

HLA genetic variation has been found to confer risk for a wide variety of diseases. Identifying these associations and understanding their molecular mechanisms is ongoing and holds promise for the development of therapeutics. Find the latest research on HLA genetic variation here.

Super-resolution Microscopy

Super-resolution microscopy is the term commonly given to fluorescence microscopy techniques with resolutions that are not limited by the diffraction of light. Here are the latest discoveries pertaining to super-resolution microscopy.

Genetic Screens in iPSC-derived Brain Cells

Genetic screening is a critical tool that can be employed to define and understand gene function and interaction. This feed focuses on genetic screens conducted using induced pluripotent stem cell (iPSC)-derived brain cells.

Brain Lower Grade Glioma

Low grade gliomas in the brain form from oligodendrocytes and astrocytes and are the slowest-growing glioma in adults. Discover the latest research on these brain tumors here.

CD4/CD8 Signaling

Cluster of differentiation 4 and 8 (CD8 and CD8) are glycoproteins founds on the surface of immune cells. Here is the latest research on their role in cell signaling pathways.

Alignment-free Sequence Analysis Tools

Alignment-free sequence analyses have been applied to problems ranging from whole-genome phylogeny to the classification of protein families, identification of horizontally transferred genes, and detection of recombined sequences. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.