Egg production in relation to paternal weight in a freshwater caridean shrimp (Decapoda)

Abstract

In diverse invertebrate species, sperm quantity and quality are positively correlated with male size, egg fertilization rates being consequently affected by paternal weight. This factor may also have an indirect effect on egg quality, because females could adjust the quantity of yolk stored in oocytes before spawning according to their partner attractiveness. The objective of this study was to determine whether paternal weight influences egg production in a freshwater crustacean with external egg fertilization, the caridean shrimp Neocaridina davidi. Virgin females weighing 60–100 mg were paired with virgin males weighing 20–50 mg. The number (total and fertilized), size (volume, wet and dry weight) and carotenoid content of eggs were recorded for each pair. Paternal weight was not associated to any of the evaluated egg variables, while maternal weight showed a positive correlation with egg number and a negative correlation with egg carotenoid content. The percentage of fertilized eggs was similar and near 100% for all paternal sizes, which indicates that small mature males provided enough good‐quality sperm to fertilize almost all the oocytes laid by females, similarly to larger males. The relatively low fecundity of N. davidi females may explain, at least in part, the absence of sperm limitation even under a hypothetical decrease in sperm supply by smaller males. In addition, paternal weight had no effect on egg volume, weight and carotenoid content, which suggests that females do not modulate the total amount of biochemical reserves allocated to the maturing ovary as a function of their partner size. Present results are the starting point for a future evaluation of sperm production, in terms of quantity and quality, in males of different size and physiological condition.

Body coloration, carotenoid content, spermatophore quality and biochemical parameters by effect of temperature in the caridean shrimp Neocaridina davidi (Atyidae)

“…Total carotenoid content both in females and males was determined spectrophotometrically (spectrophotometer Shimadzu UV‐Vis 1800) according to the methods described by Renstrøm, Borch, and Liaaen‐Jensen (1981) and Torrissen & Naevdal (1984), with modifications for N. davidi by Tropea, Sganga, and López Greco (2019). Briefly, caudal fans from animals of the same replicate at each temperature treatment were used.…”

Brothers are better than nothing: first report of incestuous mating and inbreeding depression in a freshwater decapod crustacean

“…Once detected, all ovigerous females were weighed (wet weight, precision: 0.1 mg) and eggs were gently removed from their pleopods at day 5-6 of the incubation period, when embryos were clearly visible (Tropea et al, 2019). Both the total number of eggs and the number of fertilized eggs (i.e.…”

Effect of different substrates on growth and biochemical composition of the ornamental “red cherry” caridean shrimp, Neocaridina davidi (Atyidae)

“…Previous studies have addressed several aspects of N . davidi's reproduction and growth (Marciano et al, 2018; Sganga et al, 2016; Tropea & López Greco, 2015, 2019; Tropea et al, 2015, 2019), early development (Pantaleão et al, 2015, 2017), the use of formulated diets to enhance growth and colour (Sganga & López Greco, 2020; Tomas et al, 2020), dietary supplementation with the algae Spirulina platensis (Namaei Kohal et al, 2018) and optimal density for maximum growth (Vazquez et al, 2017). Nonetheless, to our knowledge, no studies regarding the effect of vegetal cover on this species culture have been conducted.…”