1 2025 - DUE 11 April 2025; 100% correct solutions and
explanations.
Question 1 (33 marks)
1.1 Provide the complete taxonomy of the Mozambique tilapia.
(14)
1.2 What sense organs are used by sharks for the detection of
prey? (8)
1.3 What two characteristics distinguish the skeletons of
cartilaginous fish from other vertebrates? (2)
1.4 Name the organ(s) associated with maintaining buoyancy in
bony fish. (4)
1.5 Describe a heterocercal tail. (3)
1.6 Approximately what percentage of sharks’ diet contains
bony fish? (2)
1.1 Complete Taxonomy of the Mozambique Tilapia (14
marks)
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
, Family: Cichlidae
Genus: Oreochromis
Species: Oreochromis mossambicus
1.2 Sense Organs Used by Sharks for the Detection of Prey
(8 marks)
Sharks use the following sense organs:
1. Olfactory organs (Nostrils) – Detect chemical signals in
water.
2. Lateral line system – Detects water movements and
vibrations.
3. Ampullae of Lorenzini – Detects electric fields produced
by prey.
4. Eyes (Vision) – Well-developed eyesight helps in low-light
conditions.
1.3 Two Characteristics that Distinguish the Skeletons of
Cartilaginous Fish from Other Vertebrates (2 marks)
1. Their skeletons are made of cartilage rather than bone.
2. They lack true bone marrow for blood cell production.
1.4 Organ(s) Associated with Maintaining Buoyancy in Bony
Fish (4 marks)
The swim bladder is the primary organ responsible for
buoyancy in bony fish.
1.5 Description of a Heterocercal Tail (3 marks)