As far as i know you can't do that, but also you can do it like this :
local FishingSpot = createMarker(494.214, -1925.360, -0.550, 'cylinder', 5.0, 0, 0, 255, 150)
local FishingSpot2 = createMarker(469, -1941.166015625, -0, 'cylinder', 5.0, 0, 0, 255, 150)
t = { FishingSpot, FishingSpot2 }
for i = 1,#t do
setElementID( t[i], "marker"..i)
id = getElementByID("marker"..i)
blips = createBlipAttachedTo(id, 41)
end