@article {14059, title = {Alternative reproductive tactics and inverse size-assortment in a high-density fish spawning aggregation.}, journal = {BMC Ecol}, volume = {17}, year = {2017}, month = {2017 Feb 28}, pages = {10}, abstract = {

BACKGROUND: At high densities, terrestrial and marine species often employ alternate reproductive tactics (ARTs) to maximize reproductive benefits. We describe ARTs in a high-density and unfished spawning aggregation of the squaretail grouper (Plectropomus areolatus) in Lakshadweep, India.

RESULTS: As previously reported for this species, territorial males engage in pair-courtship, which is associated with a pair-spawning tactic. Here, we document a previously unreported school-courtship tactic; where territorial males court multiple females in mid-water schools, which appears to culminate in a unique {\textquoteright}school-spawning{\textquoteright} tactic. Courtship tactics were conditional on body size, local mate density and habitat, likely associated with changing trade-offs between potential mating opportunities and intra-sexual competition. Counter-intuitively, the aggregation showed a habitat-specific inverse size-assortment: large males courted small females on the reef slope while small males courted equal-sized or larger females on the shelf. These patterns remained stable across two years of observation at high, unfished densities.

CONCLUSIONS: These unique density-dependent behaviours may disappear from this aggregation as overall densities decline due to increasing commercial fishing pressure, with potentially large consequences for demographics and fitness.

}, issn = {1472-6785}, doi = {10.1186/s12898-017-0120-5}, author = {Karkarey, Rucha and Zambre, Amod and Isvaran, Kavita and Arthur, Rohan} }