Life cycle traits of Philodina roseola Ehrenberg, 1830 (Rotifera, Bdelloidea), a model organism for bioassays

Abstract

This paper describes experimental results on the life cycle of the rotifer Philodina roseola cultured in the laboratory. Detailed information on life-cycle parameters of a certain species provides a deep understanding and contributes to a better knowledge of the role of the species in the community, besides providing data that are basic to other ecological investigations such as secondary production estimates and knowledge for applications such as its utilization as test-organism in ecotoxicological studies. The average duration of embryonic development of P. roseola was 23.88 h, the age at maturity of primipara was 3.5 days and the maximum lifespan was 23 days. The average size of the rotifer neonate was 198.77 μm, the mean size of primipara was 395.56 μm and for adults 429.96 μm. The average fecundity was 1.22 eggs per female per day and the mean number of eggs produced per female during the entire life was 22.33. The deceleration of somatic growth from the start of the reproductive stage represents a trade-off between growth and reproduction that is often seen in micrometazoans. The life history of P. roseola follows the strategy of other bdelloid species characterized by a rapid pre-reproductive development and canalization of most assimilated energy to reproduction after reaching maturity. The differences observed in total fecundity and longevity between our P. roseola cultures and those from previous studies were probably due to differences of intrinsic adaptation of this species ecotypes to the conditions of their natural environments.

Freshwater toxicity testing using rehydratedPhilodinasp. (Rotifera) as test animals

“…In our Philodina species, newborns hatch from eggs at 0.4 mm in length and double in size by day 5. This species is larger than the P. roseola described by, which hatched at 0.2 mm in length, and grow to about 0.4 mm long by day 10 at 25°C, the size they remain for the rest of their lives.…”

First data on secondary production of Philodina roseola (Rotifera, Bdelloidea) grown in laboratory

“…Stock cultures of P. roseola were maintained as described by Moreira et al (2015) and Moreira et al (2016) in 50-250 mL beakers; incubators were set at 25 ± 1 • C, with a photoperiod of 16 h light:8 h darkness. Cultures reached a high den-sity (around 116 ind/mL).…”

“…Secondary production for neonates, young, and adults of P. roseola was carried out by quantifying size increments and calculating corresponding volumes for each developmental phase, as described in Moreira et al (2016). Secondary production allocated for growth (Pg) by juveniles was determined by subtracting dry weight values of juveniles from those of neonates, and the difference was divided by the development time spent from neonate to juvenile stages (in hours).…”

“…Similarly, the production of adults was determined by subtracting the average dry weight of adults from that of juveniles, and the difference was divided by development time spent from juvenile to adult stages. Average development times from neonate to juvenile stages and from juvenile to adult stages were 15.0 and 33.0 hours, respectively (Moreira et al, 2016). Summing up production values between developmental stages (neonate to juvenile and juvenile to adult), the amount of secondary production allocated to growth by P. roseola was assessed.…”

The relation between human biomarkers and oxidative stress in Alzheimer’s disease, novel in vivo experimental modelling possibilities

“…Furthermore, their native food source includes particulate organic detritus, dead bacteria, algae, and protozoa, which offer a large variety of natural aggregates [Mialet et al, 2013;Moreira et al, 2016]. Therefore, the capability of these animals to metabolize almost every type of aggregated peptides and proteins might be an evolutionary strategy for adaption and survival.…”