Mating structure of the blue and red shrimp, Aristeus antennatus (Risso, 1816) characterized by relatedness analysis

Abstract

Understanding life history variation and strategies is crucial for stock assessment and fisheries management due to the direct effects on population dynamics, effective population size, sex-ratios, levels of inbreeding, and relatedness among individuals. Aristeus antennatus (En ─ Blue and red shrimp; Fr ─ Crevette rouge; Sp ─ Gamba rosada) is one of the most exploited demersal resources in the Western Mediterranean Sea. However, information regarding the mating system and mate choice preferences remains largely unknown. Advances in molecular genetic markers and methods of inferring biological relationships among individuals have facilitated new insights into the reproductive dynamics of the species in the wild. Here, we used microsatellite markers to examine the A . antennatus mating system and putative mate choice preferences. Our results provided clear evidence of polyandry and polygyny. Relatedness analyses, together with F ST and DAPC values showed females exhibited a mating bias towards unrelated males. Mating males were inferred from spermatophores and suggested males were sympatric with females and were also from other spawning grounds. Our findings provided the first description of the reproductive behavior of blue and red shrimp.

Genetic analyses reveal temporal stability and connectivity pattern in blue and red shrimp Aristeus antennatus populations

“…Our mean observed and expected heterozygosities (H O = 0.468, H E = 0.633) were in accordance with recent studies using the same set of microsatellite loci (H O = 0.443, H E = 0.611 recalculated excluding Aa421 33 ; H O = 0.458, H E = 0.628 34 ). The mean number of alleles per locus and sample (N A = 9.1, Table 2) was slightly higher than reported previously with the same microsatellite loci (N A = 7.9 recalculated excluding Aa421 33 ; N A = 7.8 34 ), probably due to the sample size in our study almost doubling the one in those previous studies.…”

“…There are some factors that could be responsible for these deviations from HWE genotypic proportions, such as inbreeding, null alleles or subpopulation structure. According to a recent study about the mating structure of A. antennatus, most of the mating individuals of the spawning groups are not related 33 , so we did not consider inbreeding to be the cause of the HWE disequilibrium found in our results. Null alleles could explain the heterozygote deficiency, according to our results showed by Micro-checker (Supplementary Table S1).…”

“…Null alleles could explain the heterozygote deficiency, according to our results showed by Micro-checker (Supplementary Table S1). The Wahlund effect cannot be ruled out as one reason for heterozygote deficiency, due to the possibility of having www.nature.com/scientificreports/ sampled genetically differentiated subpopulations or cohorts simultaneously, as it was pointed out previously for A. antennatus 33 . Overall, our results from pairwise F ST , Isolation by distance, relative migration networks, Bayesian analysis and AMOVAs, showed a high connectivity pattern of A. antennatus fishing grounds (Tables 3, 4, Fig.…”

Genetic structure and population connectivity of the blue and red shrimp Aristeus antennatus

“…The heterozygote deficit, reflected in positive F IS values (average = 0.271; Table 1), was responsible for the observed HW deviations. We ruled out possible inbreeding, as a recent study suggested that spawning groups of this species are formed mostly by unrelated individuals 22 . We believe that this deficit may be due to the null alleles as previously observed for A. antennatus and other decapods 13,15 and in the case of WM, they could also be due to the Wahlund effect.…”

“…These molecular markers were distributed in three multiplex PCRs (sets of 3–5 loci) and one singleplex PCR for optimal amplification, following standard procedures with an annealing temperature of 50 °C or 60 °C, as described in Planella et al . 22 . PCR product sizing was performed with the GeneScan TM 500 LIZ ® size standard (Applied Biosystems) on an ABI PRISM ® 3130 Genetic Analyzer (Applied Biosystems).…”