Ultraviolet irradiation increases size of the first clutch but decreases longevity in a marine copepod

Abstract

An important component of life history theory is understanding how natural variation arises in populations. Both endogenous and exogenous factors contribute to organism survival and reproduction, and therefore, it is important to understand how such factors are both beneficial and detrimental to population dynamics. One ecologically relevant factor that influences the life history of aquatic organisms is ultraviolet (UV) radiation. While the majority of research has focused on the potentially detrimental effects that UV radiation has on aquatic organisms, few studies have evaluated hormetic responses stimulated by radiation under select conditions. The goal of this study was to evaluate the impact of UV‐A/B irradiation on life history characteristics in Tigriopus californicus copepods. After exposing copepods to UV‐A/B irradiation (control, 1‐, and 3‐hr UV treatments at 0.5 W/m2), we measured the impact of exposure on fecundity, reproductive effort, and longevity. We found that UV irradiation increased the size of the first clutch among all reproducing females in both the 1‐ and 3‐hr experimental groups and decreased longevity among all females that mated in the 1‐hr treatment. UV irradiation had no effect on the number of clutches females produced. These findings indicate a potential benefit of UV irradiation on reproductive performance early in life, although the same exposure came at a cost to longevity.

Comparison of UVC Sensitivity and Dectin-2 Expression Between Malignant and Non-malignant Cells

“…Moderate doses of UV exert several favorable effects such as induction of vitamin D biosynthesis (18), hormetic response in normal oral cells (19) and plant tissues (20,21), and increase in reproductive performance early in life (22).…”

WITHDRAWN: Responses of the Ecological Characteristics and Antioxidant Enzyme Activities in Rotaria Rotatoria to UV-B Radiation

“…Ultraviolet radiation is an important case of exogenous factor that is ecologically relevant for smallbodied invertebrates [9]. Over the past few decades, it has been well demonstrated that nature ultraviolet-B (UV-B) radiation increased signi cantly with the continuing depletion of stratospherico zone, which has becoming one of the grave concerns and most striking global changes [10,11].…”

A combination of red structural and pigmentary coloration in the eyespot of a copepod

“…If these are not spheres, for instance if they are continuous tubes, we would expect some amount of variation in the cross sections, which we did not observe. The presence of one or two air layers throughout the exoskeleton could be advantageous to copepods by reflecting UV light and aiding in protection against UV radiation that is known to significantly influence survival and reproductive success in copepods that live in shallow splash pool habitats [41][42][43]. Carotenoids in both the body and eyespot additionally contribute to UV light absorption and, thereby, aid in UV protection.…”