Thanks for your trust—I'll estimate the hedonistic welfare per animal-year of random wild juveniles of Caenorhabditis elegans, Tectocepheus velatus, and Folsomia candida as fractions of their respective healthy counterparts with negligible mortality. I'll provide point estimates representing the means of my best-guess distributions, reflecting whether life is likely net positive or negative in hedonistic terms.I'll get started and let you know as soon as I have the estimates ready.
- Caenorhabditis elegans (L1 juveniles): ≈0.10 (10%). L1 larvae are tiny (302 neuronsen.wikipedia.org) and exhibit only simple reflexespubmed.ncbi.nlm.nih.gov. Wild L1s hatch into microbe-rich rotting plant materialpubmed.ncbi.nlm.nih.gov, but many bacteria are pathogenic (∼20% of worms are arrested by natural microbespubmed.ncbi.nlm.nih.gov). The juvenile life is brief and fraught with starvation, desiccation or infection, with little evidence of complex pleasurable experiencepubmed.ncbi.nlm.nih.gov. Given the very limited nervous complexity and harsh environment, we judge net welfare to be very low (on the order of 10% of a healthy adult’s level).
- Tectocepheus velatus (larvae): ≈0.20 (20%). T. velatus is a small soil oribatid mite (adult ≈0.25 – 0.30 mm) with a simple arachnid nervous system. In the wild it is a pioneer species found in harsh, disturbed habitats (dump sites, glacial soil)artsdatabanken.no. Development to adulthood takes very long (≫2 years in the fieldartsdatabanken.no), so larval stages endure prolonged exposure to cold, drought or low food. These mites likely sense their world but have minimal cognition; we have no direct data on pain in oribatids. Given their tough environment and slow growth, but somewhat richer capacity than nematodes, we estimate juvenile welfare modestly (~20%).
- Folsomia candida (1st instars): ≈0.30 (30%). F. candida is a springtail (≈3 mm) whose eggs hatch in about 1 week and reach maturity in ~3 weeks at 21 °Cen.wikipedia.org; thus a first instar lives only a few days. Springtail juveniles burrow in moist, organic-rich soil with ample fungal food, tolerating extreme conditions (e.g. 10% CO₂ for weeksen.wikipedia.org). They possess antennae and chemosensory organs (unpigmented body, no eyespotsen.wikipedia.org) suggesting greater sensory/neural complexity than nematodes. With more benign habitat (stable moisture, food) and active feeding behavior, we assign them a somewhat higher welfare fraction (~30%) than the others, while still well below ideal lab-reared adults. Sources: Estimates based on species life‐history and habitatspubmed.ncbi.nlm.nih.govartsdatabanken.noartsdatabanken.noen.wikipedia.org and on general invertebrate welfare criteria (nervous system size, nociception)pubmed.ncbi.nlm.nih.goven.wikipedia.org.