Drug-induced shrinkage of nematodes

I am conducting research where I am investigating the effects of f-mocleucine and celecoxib on Caenorhabditis elegans. I have noticed that as the nematodes are incubated with the drugs for longer periods of time, the number of nematodes with smaller sizes increases. The nematodes cannot reproduce because they have been sterilised and their total number decreases each day of incubation. I have also ruled out dauer larvae because these small individuals are short, usually very mobile, but no other changes can be seen on them that could be the result of the drugs. I noted similar observations with paclitaxel, fulvestrant and lapatinib. This situation occurred only with the nematodes treated with the drugs, it did not occur in the control trials. And I have a question, does anyone know where such differences in lengths can come from? Has anyone also observed such a situation, or knows whether nematode shrinkage or the formation of a non-dauer spore form is possible with C. elegans?