artes fijas

05:34 Mar 23, 2018 

https://books.google.com/ngrams/graph?content=los artes de p...

In the case of "artes fijos" versus "artes fijas", the masculine was much more common up to the 1930s. From about 1950-1990 there were many more instances of "artes fijas", but now they are more or less equally common:
https://books.google.com/ngrams/graph?content=artes fijos,ar...

05:31 Mar 23, 2018 

This has changed over time. In the 19th century the Academy dictionary said that although "arte" always takes a masculine article in the singular, to avoid cacophony, you can put the adjective in whichever gender sounds better; both "el arte diabólico" and "el arte diabólica" are acceptable. They stopped saying this around 1900. In 1840, in his Gramática de la lengua castellana según ahora se habla, Vicente Salvá said that in the plural "artes" takes feminine adjectives when referring to "profesiones o ramos" (las bellas artes, las artes liberales) but otherwise it's usually masculine, and he gives the examples "los artes para coger pezes", "los artes de la gramática y de la retórica".
https://books.google.es/books?id=msNRNJ7mf9UC&pg=PA21

Google's Ngram viewer shows that until around 1930 "los artes de pesca" and "las artes de pesca" were more or less equally common, but since then "las artes de pesca" has increasingly been the predominant form and it is now about five times as common as "los artes de pesca".

(Continued in next post)

05:15 Mar 23, 2018 

The RAE and all modern grammarians I have consulted agree that arte is usually masculine in the singular and feminine in the plural, though the DLE continues to list it as "m. o f." in all senses of the word. See the DPD, which says "cuando va en plural, lo normal es usarlo en femenino", and includes an example of "las artes de pesca" but none of "los artes de pesca":
http://lema.rae.es/dpd/?key=arte

I don't think anyone would say "bellos artes"; it's always "bellas artes". However, quite a lot of fishery sources, including legal and administrative documents in Spain, refer to "los artes de pesca". It would seem, therefore, that for at least some speakers the gender of "artes", plural, varies according to the sense: they treat it as feminine when it refers to arts and masculine when it refers to fishing gear.

(Continued in next post)