Bose, Aneesh
- Institutionen för vilt, fisk och miljö, Sveriges lantbruksuniversitet
Sammanfattning
The plainfin midshipman (Porichthys notatus Girard, 1854) is a toadfish with two distinct reproductive male tactics: 'guarder males' and 'sneaker males'. These two tactics are anatomically, physiologically and behaviourally distinct from one another at sexual maturity, but it remained unclear whether these two male types remain fixed or plastically transition from one to another across a lifetime. To examine this question, we aged the sagittal otoliths (inner ear bones) of 371 adult plainfin midshipman via the break-and-burn method. Our study showed that guarder males were on average larger and older (mean age: 7.0 years, range: 3-17) than sneaker males (mean age: 3.4 years, range: 2-8) and females (mean age: 5.1 years, range: 2-10). There was considerable overlap in age between guarder and sneaker males; the two tactics were of similar body sizes at age 3, but after that guarder males were always bigger. We used a two-factor von Bertalanffy growth functions (VBGFs) to show that males versus females and guarder versus sneaker males had divergent growth trajectories. The VBGF estimates and distance measures from the otolith centre to the first annual otolith mark suggest that sneakers initially grew more quickly. Our results support the hypothesis that the two male reproductive tactics in plainfin midshipman likely represent distinct fixed life-history pathways that differ early in their development.
Nyckelord
ageing; Batrachoididae; life history; ontogeny; otoliths; Porichthys notatus; toadfish; von-Bertalanffy growth function
Publicerad i
Journal of Fish Biology
2025
Utgivare: WILEY
SLU författare
UKÄ forskningsämne
Fisk- och akvakulturforskning
Ekologi
Publikationens identifierare
- DOI: https://doi.org/10.1111/jfb.70274
Permanent länk till denna sida (URI)
https://res.slu.se/id/publ/144885