7-7 Population structure, evolutionary history, and genomic vulnerability of cryptobenthic fishes in the Gulf of California

Session: Earth Life Sciences across the Cordillera (Posters)

Poster Booth No.: 13

Presenting Author:

De Jesús-Bonilla

Authors:

, De Jesús-Bonilla Vladimir Salvador¹, Valenzuela-Quiñonez, Fausto², Mac Loughlin, Camila³, Hernández Saavedra, Norma Yolanda⁴, Salazar, Salwa El Khattabi⁵

(1) Fisheries Ecology, Centro de Investigaciones Biológicas del Noroeste S.C., La Paz, Baja California Sur, Mexico, (2) Fisheries Ecology, Centro de Investigaciones Biológicas del Noroeste S.C., La Paz, Baja California Sur, Mexico, (3) Fisheries Ecology, Centro de Investigaciones Biológicas del Noroeste S.C., La Paz, Baja California Sur, Mexico, (4) Fisheries Ecology, Centro de Investigaciones Biológicas del Noroeste S.C., La Paz, Baja California Sur, Mexico, (5) Fisheries Ecology, Centro de Investigaciones Biológicas del Noroeste S.C., La Paz, Baja California Sur, Mexico,

Abstract:

The Gulf of California is a region characterized by high biological diversity and elevated levels of endemism. Its complex geological history, coupled with the presence of environmental gradients, offers a unique opportunity to investigate how historical and contemporary processes shape marine genomic diversity and what their implications are in the face of climate change. In this study, we analyzed the population structure of three species of cryptobenthic fishes: Elacatinus puncticulatus, Acanthemblemaria crockeri, and Crocodilichthys gracilis. Using ddRADseq genomic sequencing across populations distributed along the gulf, between 3,800 and 8,800 SNPs were obtained per species, a subset of which corresponded to candidate loci under selection or outliers. The results revealed pronounced genetic differentiation between northern and southern regions and restricted connectivity, as well as a diversification scenario involving secondary contact between lineages. Ecological niche modeling was used to compare current distributions with projections from the Last Glacial Maximum, identifying historical refugia that likely acted as reservoirs of diversity. In parallel, genome–environment associations revealed variants linked to climatic gradients, particularly temperature, highlighting the adaptive potential of these species. However, genomic vulnerability, understood as the mismatch between current variants and future environmental conditions, varied among species, suggesting uneven risks under climate change. These results suggest that geological history, environmental heterogeneity, and contemporary oceanographic dynamics have all contributed to shaping the genomic structure of these populations. Together, this study integrates historical, ecological, and genomic perspectives to understand the structure and resilience of cryptobenthic fishes. The findings underscore the importance of incorporating both evolutionary legacies and global change scenarios into the design of conservation strategies that ensure the persistence of marine biodiversity in the Gulf of California.

 

Geological Society of America Abstracts with Programs. Vol. 58, No. 3, 2026

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