(Read part 1 of this series) or (Read part 2 of this series) After writing down specific markings I see on a fish, I make note of the basic body shape of the fish and some of the defining characteristics of it's shape. The basic knowledge of fish anatomy comes in handy (Fish Identification Part 2) so that you know which parts of the fish to observe. Sometimes a quick sketch is faster than writing all of this down. Markings and body patterns
markings and body patterns
The overall shape and markings on a fish are the first thing that I make a note of when I am struggling to identify a fish. Many fish fall into the same family group and can be difficult to distinguish. The shape of a fish's body depends on the fish's habits. Some fish are more streamlined for faster swimming. Some have narrow bodies that allow them to hide in tight spaces. Some things to look for include: body shape, dorsil fin position and shape, mouth shape, and the tailfin shape.

Mouth shapes

mouth shapes
Source The size, proportion, position and shape of a fish's mouth are very distinctive. Some fish appear to have whiskers or a pointed tip. Others have big lips.

Fin shapes

fin shapes
Source The makeup of a fish's dorsil fin (the fin running across it's back) can be very distinctive at times. Some are continuous and have no breaks, others are notched and appear to have spines on them.

Tail shapes

tail shapes
Source The shape of a fish's tail-fin can be the main identifier sometimes. On a Dive Addicts, 2006 trip to Little Cayman I was able to gather an impressive list of fish. The diving that week was absolutely superb. Great viz, great weather, uncrowded dive sights, and the Bloody Bay Wall. What could be better. 25 Dive Addicts all enjoying each others company, and enjoying the resort, diving and food!
The reefs have were in great shape. Hurricane Ivan had passed that way almost two years before and hit Grand Cayman. There was very little damage in Little Cayman. =Almost everyone on the trip saw new creatures they hadn't seen before. (See my fish list below for her personal list of underwater life sighted.) The wall in the Bloody Bay Marine Park was just spectacular. It is as sheer as they come, and covered with an incredible amount of various sponges, hard coral and soft coral. We saw sharks, turtles, sting rays, eagle rays, as well as dozens of the typical Caribbean characters. We couldn't have asked for a better week of diving!
My Little Cayman Fish List: Juvenille Spotted Drum, Rainbow Parrot Fish, Spotted Scorpion Fish, Green Morray Eel, Spotted Eagle Ray, Southern Sting Ray, Honey Comb Cowfish, Porcupine Fish, Balloon Fish, Princess Parot Fish, Gray Angelfish, Tiger Grouper, Nasau Grouper, Black Grouper, Graysby, Four-eye Butterfly fish, Banded Butterfly fish, Rock Beauty, Queen Angelfish (juvenille and adult), Docotrfish, Horse-eye Jack, Cero, Great Baracuda, Blue-striped Grunt, School Master, Ceasar Grunt, Red Hind, Tabacco Fish. Fairy Basslet, Spotlight Parrot Fish- male and female, Striped Parrot Fish- male and female, Red band Parrot Fish, hogfish, Bluehead, Blue Tang, Squirrel Fish, Long Jaw Squirrel Fish, Neon Goby, Goldspot Goby, Masked Goby, Briddled Goby, Sand Diver, Trumpet Fish, Peacock Flounder, Yellowhead Jawfish, Black Durgon, Queen Triggerfish, Nurse Shark, Carribean Reef Shark, Spiny Lobster, Brittle Star, Lettuce Sea Slug, Banded Coral Shrimp, Arrow Crab, Flame Scallop, Sea Star, Spotted Morray, Flamingo Tongue Snail, Brittle worm, Atlantic Octopus, Arrow Blemy, Red Spotted Lobster, Urchin Crab