Five new Caenorhabditis species from Indonesia provide exceptions to Haldane's rule and partial fertility of interspecific hybrids. - Devi MP; Haryoso E; Rais EI; Karuniawan A; Yahya MQ; Richaud A; Wang J; Rockman MV; Tarno H; Félix MA (BioRxiv : the preprint server for biology, 2025)