Although muricid snails are an important ecological and fisheries resource in northwest Mexico, information on their allometry and morphometry is scarce. For one year (February 2022-January 2023), 30 specimens of the “Chinese black” snail, Hexaplex nigritus (shell height = 101.4 ± 13.7 mm, total snail weight = 192.3 ± 89.1 g) were monthly collected from a coastal lagoon of the southeastern Gulf of California. The biometrics of shells (height SH, length SL, width SW, and shell opening width WSO) and operculum (height OH, length OL, and width OW) and weight variables (total snail weight TWS, total hell weight TSW, total tissue weight TTW, total gonad weight TGW, and total operculum weight TOW) of sampled snails were morphometrically analyzed. All biometric indicators of the snail shell and operculum showed significant differences (P < 0.05) monthly and presented linear and positive equations in all associations. The SH/SL relationship represents the most appropriate tool to describe the relative growth of this gastropod (coefficient of determination, R2 = 0.80), considering an empty shell; meanwhile, TWS/SL better describes the shell/weight interaction (R2 = 0.80) for live snails. The water temperature showed a positive correlation with the biometric indicators. The measurements obtained from the shell dimensions of this gastropod indicate that the sampled population consisted of adult snails. These data are fundamental for the management and conservation of this muricid species in the study area, providing valuable information for planning sustainable management strategies.

The artisanal harvesting of Anadara mazatlanica is of fundamental importance to the sociocultural identity and economic livelihood of the coastal communities located in the San Ignacio–Navachiste–Macapule (SINM) lagoon system in Mexico; its conservation depends on the sustainable use of the species and its habitat, which is considered vulnerable to multiple socioeconomic and environmental pressures. The circular economy (CE) emerges as a potential approach to integrate resource exploitation, waste reduction, and community-oriented conservation management. This study analyzed the perceptions of A. mazatlanica harvesters, covering social, economic, environmental, and recycling dimensions (theoretical approach) and corroborated by exploratory factor analysis, thereby identifying the main challenges and areas of opportunity for the transition to sustainable development models. A quantitative (exploratory–descriptive) approach was used, employing a structured questionnaire that included a sociodemographic section and 23 items on a Likert scale. The findings revealed a high sociocultural appreciation of artisanal fishing and community cohesion ($\overline{\mathrm{x}}$ = 4.55). In contrast, economic perceptions showed a moderately negative level ($\overline{\mathrm{x}}$ = 2.48), indicating a dependence on intermediaries, limited added value, and institutional support. The CE dimension ($\overline{\mathrm{x}}$ = 1.55) suggested an underutilization of shells. In addition, the mean value of 3.44 for environmental perceptions highlighted awareness of ecosystem deterioration and regulatory deficiencies. These results highlight the need to enhance fisheries governance, diversify value chains, and integrate circular innovations to ensure the sustainability of this fishery.

Perkinsus marinus is a myzozoa parasite native to the eastern coast of the United States, where it has been associated with significant mortalities in bivalve mollusk populations. Over the past two decades, its presence has been documented in various shellfish species—including oysters, clams, mussels, and scallops—along the Gulf of California (GC), leading to its classification as a widely distributed exotic invasive species. To assess the occurrence of P. marinus in the marine gastropod Hexaplex nigritus, thirty specimens were collected monthly from the Navachiste lagoon (NL, southeastern GC) between February 2022 and January 2023 (n = 360). The presence of presumptive hypnospores was detected using Ray’s thioglycolate fluid medium, while polymerase chain reaction analysis confirmed P. marinus in the digestive gland of H. nigritus. The pathogen was detected at a prevalence of 6.66% in October (annual prevalence = 0.6%), exhibiting low infection intensity (<104 hypnospores g−1 of tissue), indicative of a non-pathogenic or subclinical condition. Sequencing of the amplified product revealed 99.34% similarity with P. marinus sequences available in GenBank (accession number OR936656.1). This study represents the first record of the parasite P. marinus infecting the marine snail H. nigritus in NL, Sinaloa, Mexico. The finding broadens the known host range of this parasite and suggests that H. nigritus may play a potential role in its dispersal and transmission within the local food web, with possible implications for regional biodiversity and fisheries management.