
click to enlarge
There are several familiars that you can call using the
Summoning skill that will boost your Fishing abilities. Among them are the Granite Crab, Ibis, and Granite Lobster. The bonuses given by these familiars are invisible so they won't help you catch higher level fish or get into the Fishing Guild at an earlier level, but they can help you be faster and more efficient at catching the fish available at your normal level.
The Granite Crab can be called with a Summoning level of 16. In addition to giving a +1 invisible boost to Fishing, the familiar will also forage for cod, pike, seaweed, and oysters while you are fishing.
With Summoning level 56, you can call the Ibis. This familiar gives an invisible boost of +3 to your Fishing level. Also, while you are fishing, the Ibis will forage for tuna and swordfish. It will even give you a small bit of Fishing experience when it manages to find a swordfish.
The Granite Lobster is a familiar that can be called at Summoning level 74 and is quite popular with those who have a high enough level to summon it. It gives an invisible boost of +4 to your fishing level and forages for swordfish and sharks even if your Fishing level isn't high enough for you to catch these fish on your own. Also, it will shift some of the Fishing experience from these catches to you, making it a great companion if you're trying to train quickly.