Socially parasitic ants of the formicoxenine genus Myrmoxenus exhibit considerable diversity in colony structure and life history.While some species are active slave-makers with many workers and others are workerless...Socially parasitic ants of the formicoxenine genus Myrmoxenus exhibit considerable diversity in colony structure and life history.While some species are active slave-makers with many workers and others are workerless‘murder-parasites,’Myrmoxenus kraussei is considered as a‘degenerate slave-maker’because of its very low worker numbers.Here,we document that Temnothorax recedens host workers in single colonies of M.kraussei from Lago di Garda,Italy,exhibit significantly more genetic diversity than workers in unparasitized colonies.This raises the possibility that,despite its low worker numbers,M.kraussei may actively engage in slave raids in nature.展开更多
Size and shape of sperm cells vary tremendously throughout the animal kingdom.The adaptive significance of this variation is not fully understood.In addition to sperm-female interactions and the environmental condi...Size and shape of sperm cells vary tremendously throughout the animal kingdom.The adaptive significance of this variation is not fully understood.In addition to sperm-female interactions and the environmental conditions,the risk of sperm competition might affect number,morphology and other“quality”traits of sperm.In the male-diphenic ant Cardiocondyla obscurior,winged sneaker males have limited sperm number,because their testes degenerate shortly after adult emergence,as is typical for males of social Hymenoptera.In contrast,wingless fighter males continuously replenish their sperm supply due to their exceptional lifelong spermatogenesis.While winged males usually have to compete with several other winged males for virgin queens,wingless males are able to monopolize queens by killing all other rivals.Hence,this presents a unique system to investigate how alternative reproductive tactics and associated physiology affect sperm morphology and viability.We found that sperm-limited males invest into sperm number instead of sperm size.Variance in sperm length is smaller in winged males,probably reflecting that they have to compete with several other males.Finally,sperm viability is equally high in both male phenotypes.展开更多
基金We thank Daniela Schulz for technical assistance and DFG(He1623/24)for financial support.
文摘Socially parasitic ants of the formicoxenine genus Myrmoxenus exhibit considerable diversity in colony structure and life history.While some species are active slave-makers with many workers and others are workerless‘murder-parasites,’Myrmoxenus kraussei is considered as a‘degenerate slave-maker’because of its very low worker numbers.Here,we document that Temnothorax recedens host workers in single colonies of M.kraussei from Lago di Garda,Italy,exhibit significantly more genetic diversity than workers in unparasitized colonies.This raises the possibility that,despite its low worker numbers,M.kraussei may actively engage in slave raids in nature.
文摘Size and shape of sperm cells vary tremendously throughout the animal kingdom.The adaptive significance of this variation is not fully understood.In addition to sperm-female interactions and the environmental conditions,the risk of sperm competition might affect number,morphology and other“quality”traits of sperm.In the male-diphenic ant Cardiocondyla obscurior,winged sneaker males have limited sperm number,because their testes degenerate shortly after adult emergence,as is typical for males of social Hymenoptera.In contrast,wingless fighter males continuously replenish their sperm supply due to their exceptional lifelong spermatogenesis.While winged males usually have to compete with several other winged males for virgin queens,wingless males are able to monopolize queens by killing all other rivals.Hence,this presents a unique system to investigate how alternative reproductive tactics and associated physiology affect sperm morphology and viability.We found that sperm-limited males invest into sperm number instead of sperm size.Variance in sperm length is smaller in winged males,probably reflecting that they have to compete with several other males.Finally,sperm viability is equally high in both male phenotypes.
