Influence of temperature on life history traits of the free-living, bacterial-feeding nematode Panagrolaimus sp. strain NFS-24

Abstract

Life cycle analysis data of the free-living, bacterial-feeding Panagrolaimus sp. strain NFS 24-5 were assessed at different temperatures using a hanging drop method with single male and female individuals and a food density of 3 x 10^ Escherichia coli cells ml"'. Lifespan at the moment when the first egg was laid was 5.7 days at 21°C and 4 days at 25, 27 and 29°C. The intrinsic rate of natural increase (rm) was 0.53 at 2rC, 0.81 at 25°C, 0.93 at 27°C and 0.81 at 29°C, corresponding to population doubling times (PDT = \n2/rm) of 1.3, 0.9, 0.7 and 0.9 days, respectively. Over 200 offspring per female were produced at 27°C. All other temperatures yielded fewer offspring. When females were kept without males, the life span was 49 days, whereas the last reproductive female (banging drop with male individual) died after 16.5 days. These data will contribute to the interpretation of nematode population dynamics recorded in liquid eulture.Keywords -aquaculture, fecundity, generation time, intrinsic rate of natural increase, life history trait analysis, lifespan, offspring production, population doubling time.As catches of marine fish have decreased during the past decades, aquaculture production is gaining importance. Future production of crustaceans and fish species depends on increasing demands for high quality food. During the early stages of development, marine crustacean and fish larvae rely on iive food. Feeding of iarvai stages of the brine shrimp Artemia is standard feed for crustacean larvae all over the worid. However, natural resources are limited (Focken et al, 2006). A possible alternative to Artemia are free-living, bacterial-feeding nematodes (Rhabditida). Biedenbach et al (1989) used Panagrellus redivivus L. with aigae as a larvai diet for the white shrimp Litopenaeus vannamei Boone and found significantly better results compared to the typical Artemia diet. However, this nematode cannot be desiccated. Therefore, Honnens & Ehiers (2013) proposed to use the free-living nematode Panagrolaimus sp. (strain NFS 24-5) as a potential food organism as it can easily survive desiccation and thus facilitate the development of a product formulation that is stable during stor-, but precise knowledge on the biology of this nematode is scarce. A cost-efficient production process demands maximum yields and short process time (Ehlers, 2001;Hirao & Ehlers, 2009). Optimum temperature is an important factor for improving a mass production process. Knowledge on iife history traits and growth parameters of a nematode can possibly improve the mass production process. Life cycle analysis data provides detailed information to understand the biological approach of a nematode species, i.e., the nematode's age at sexuai maturity, iifespan, net reproductive rate, totai fertiiity rate, generation time, intrinsic rate of natural increase, population doubling time and somatic growth rate. This study analysed the life cycle of the free-iiving, bacterial-feeding Panagrolaimus sp. strain NFS 24-5 at different temperatures by a recently ...

Effects of a broad range of experimental temperatures on the population growth and body-size of five species of free-living nematodes

“…Although much remains to be learned about the thermal physiology and ecology of free-living nematodes, each nematode species presumably has an optimal temperature range, one that favors population growth and is generally consistent with its biogeographic distribution (Anderson and Coleman, 1982;Venette and Ferris, 1997). Outside this thermal optimum, metabolic rates are altered and egg development may be delayed or cease until more favorable conditions return (Wharton, 2002;Ayub et al, 2013).…”

Life history trait analysis of the entomopathogenic nematode Steinernema riobrave

“…and Poikilolaimus sp., which took 2.24 and 4.21 days, respectively (Muschiol & Traunspurger, 2007). Recently, Ayub et al (2013) recorded relatively closer rm (0.81) and PDT (0.9) days for Panagrolaimus sp. (strain NFS 24-5) at 25 °C.…”

Life-History Traits of the Model Organism Pristionchus pacificus Recorded Using the Hanging Drop Method: Comparison with Caenorhabditis elegans

“…Nevertheless, the population increases of other rhabditid nematodes, as determined in other studies, were much smaller: For instance, Panagrolaimus sp. (strain NFS-24) had a population increase of 0.53 at 21°C [ 39 ]. Panagrolaimus sp.…”