Page 272 - Zoo Animal Learning and Training

244 Box B13 The ognitive Abilities oo ish

VetBooks.ir in a rectangular arena and then remove the their night time foraging patches is passed on
via social learning. It is believed that the
beacons, they can use the geometry of the
arena to locate a reward, or at least narrow it
(Gadus morhua) are also based on cultural
down to one of two alternative locations breeding migration routes of Atlantic cod
(Warburton 1990). Once they have learnt the traditions (Brown and Laland 2011).
location they can remember it for a stagger- While vision is important to many fish, che-
ing amount of time. For example, it took just mosensory cues are arguably more important.
five trials for rainbowfish to reliably locate a The reason for this is simply that fish live in an
hole in an approaching trawl net out and they aquatic medium, which is highly suited to the
retained the information for more than a transmission of chemical information (see
year (Brown and Warburton 1999). At the also Box A3). The sense of smell in fish is far
top end of the spatial learning continuum, more powerful than most terrestrial animals
fish are also capable of developing cognitive and fish are capable of detecting chemicals at
maps. A classic example is intertidal gobies concentrations lower than one in a billion
(Bathygobis soporator) which explore the (Brown and Chivers 2006). Chemosensory
surrounding rock platform at high tide and recognition plays a vital role in just about
return to their home pool to sit out the low every aspect of a fish’s life. Obviously they can
tide (Aronson 1951). Studies have shown that recognise various food items by smell, but
these fish are nearly always found in their they can also recognise each other and poten-
home pools. Even if they are displaced they tial predators (Brown and Chivers 2006). If
quickly return. When these fish are threat- given a choice between the smell of a familiar
ened during low tide, they can jump into and an unfamiliar conspecific they will move
neighbouring pools. They cannot see these towards the smell of a familiar fish (Ward and
pools but they know their location based on Hart 2003). They can also detect the differ-
the spatial map they built up during their ence between related and unrelated individu-
high tide excursions. Fish can also do time– als based on smell alone. While predator
place learning where they must keep track of recognition can be partly innate in some spe-
time and location simultaneously. A classic cies of fish, many can learn to associate the
example is when convict cichlids (Cichlasoma smell of alarm pheromones with the appear-
nigrofasciatum) gather at a feeding spot in ance of a predator. Naive fish can be rapidly
anticipation of food arriving (Reebs 1993). trained in effective predator avoidance in this
Guppies trained to locate a specific forag- manner (e.g. Brown and Laland 2011). Fish
ing patch can pass that information on to can use smell for orientation. For example,
naive individuals through a process of social many salmonids return to their natal streams
learning. Experiments show that even after as breeding adults using chemosensory cues
the trained individuals are removed from the (Dittman and Quinn 1996).
school, the naive fish retain the information. Water is also a very good medium for
Information can pass horizontally (i.e. with a sound (see also Box A2). Fish are mostly
generation) or vertically (between genera- made of water and they are surrounded by
tions; Brown and Laland 2011). When social water which means sound waves can travel
information passes between generations through the fish to activate the sensory cells
there is the possibility to establish population directly. Moreover sound travels faster and
specific cultural traditions as is the case with attenuates less quickly under water than in
many song birds. Field studies have shown air, which means there is ample opportunity
that many migration routes are maintained for fish to use hearing to sample their world.
by cultural transmission (Brown and Laland Research has shown that fish communi-
2011). For example, the daily migration cate using sound in a variety of contexts
movements of French grunts (Haemulon fla- including mating and aggressive interactions
volineatum) from their daily hiding spots to (e.g. damsel fish; Myrberg et al. 1986). There