Occurring in clusters of 5-7 individuals, on coralline algae in midintertidal zone of rocky beach.
Genus and tentative species ID from the key in Child 1979 and the description of A. californicus provided here:
León-Espinosa, Angel De, León-Gonzalez, Jesus Angel De & Gómez-Gutiérrez, Jaime, 2021, Pycnogonids from marine docks located along the west coast of the Gulf of California, Mexico, Zootaxa 4938 (2), pp. 151-195: 183-184

Full text reference: https://www.researchgate.net/publication/349638086_Pycnogonids_from_marine_docks_located_along_the_west_coast_of_the_Gulf_of_California_Mexico/download?_tp=eyJjb250ZXh0Ijp7ImZpcnN0UGFnZSI6InB1YmxpY2F0aW9uIiwicGFnZSI6Il9kaXJlY3QifX0

https://www.inaturalist.org/observations/162510081