| WBPhenotype:0000688 | sterile | Animals generate defective gametes, are otherwise unable to reproduce or they generate progeny that are unable to reproduce. | 
          
              | WBPhenotype:0001260 | oocyte morphology variant | Haploid female germ cells (oocytes) exhibit variations in their overall structure, appearance or contents compared to control. | 
          
              | WBPhenotype:0000050 | embryonic lethal | Animals die during embryonic development. In C. elegans, often assayed as refractile eggs that fail to hatch; when applied to large-scale RNAi screens in C. elegans, more than 10% of embryos die. | 
          
              | WBPhenotype:0000059 | larval arrest | The developmental program of the animals halts at any larval stage and thus fails to reach adulthood. In C.elegans, this occurs anytime during L1-L4 stage. |