return a table of species fooditems
length_freq( species_list = NULL, fields = NULL, server = getOption("FISHBASE_API", "fishbase"), version = get_latest_release(), db = default_db(server, version), ... )
A vector of scientific names (each element as "genus species"). If empty, a table for all fish will be returned.
a character vector specifying which fields (columns) should be returned. By default, all available columns recognized by the parser are returned. Mostly for backwards compatibility as users can subset by column later
can be set to either "fishbase" or "sealifebase" to switch between databases. NOTE: it is usually easier to leave this as NULL and set the source instead using the environmental variable `FISHBASE_API`, e.g. `Sys.setenv(FISHBASE_API="sealifebase")`.
a version string for the database, will default to the latest release. see [get_releases()] for details.
unused; for backwards compatibility only