Class: Senior Secondary School 1 (SS1 / SSS 1)
Term: 3rd Term
Week: 4
Age: 15 years
Duration: 45 minutes
Subject: Fisheries
Curriculum Theme: Trade
Previous Lesson: Culture Fisheries: Common Cultural Fish Species and Clarias Spp.
Topic: Characteristics of common culturable fish species
Subject Matter: Presence or absence of scales, Shape of mouth, Tail and fins, General body shape

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Identify the presence or absence of scales on different fish species.
Describe various shapes of fish mouths.
State the different types of fish tails and fins.
Classify fish based on their general body shapes.

Affective Domain:

Appreciate the diversity in physical characteristics of culturable fish species.
Value the importance of identifying specific features for fish management.

Psychomotor Domain:

Observe and differentiate characteristics from provided fish specimens or images.
Sketch simple representations of different fish body parts.

Participate in discussions about fish identification.
Collaborate with peers to identify fish characteristics.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Senior Secondary Schools.
State Unified Scheme of Work for Fisheries, Senior Secondary 1.
Adekunle, J.A. (2018). Comprehensive Fisheries for Senior Secondary Schools. Ibadan: University Press PLC.
https://www.fisheries.gov.ng/curriculum-guidelines
https://www.fao.org/fishery/en/aquaculture/species

Instructional Materials

The teacher will teach this lesson with the aid of:

Charts showing close-up images of fish scales, mouths, fins, and tails.
Assorted preserved fish specimens (e.g., Catfish, Tilapia, Mackerel).
Pictures or diagrams of various fish body shapes.

Rationale for the Lesson

This lesson helps pupils understand the physical differences between common fish species. This knowledge is important for identifying fish, selecting suitable species for aquaculture, and understanding their feeding habits and movement patterns.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of fish and their external parts from their earlier studies.

Lesson Content/Board Summary

Characteristics of Common Culturable Fish Species

Presence or Absence of Scales

Scales are small, rigid plates that grow out of the skin of a fish. They provide protection to the fish body.

Culturable fish species can be grouped based on their scales:

Scaled fish: These fish have scales covering their bodies. Examples include Tilapia, Carp, and Mackerel.
Scaleless fish: These fish do not have scales. Their skin is often smooth or covered with mucus. Examples include Catfish and Eels.

Shape of Mouth

The shape and position of a fish’s mouth are adapted to its feeding habits and can be used for identification.

Common mouth shapes and positions include:

Terminal mouth: Located at the very end of the head, pointing forward. Suitable for mid-water feeding. Example: Tilapia.
Superior mouth (Upturned): Located at the top of the head, opening upwards. Suitable for surface feeding. Example: Some types of Mudfish.
Inferior mouth (Downturned): Located on the underside of the head, opening downwards. Suitable for bottom feeding. Example: Catfish.
Protrusible mouth: Can be extended forward to suck in food. Example: Carp.

Tail and Fins

Fins are membrane-covered bony or cartilaginous rays that help fish to swim, balance, and steer. The tail fin (caudal fin) is the primary organ for propulsion.

The main types of fins are:

Dorsal fin: On the back, helps with stability.
Pectoral fins: Paired fins on each side, behind the gills, used for steering and braking.
Pelvic fins: Paired fins on the belly, below or behind pectoral fins, also for stability and steering.
Anal fin: On the underside, behind the anus, helps with stability.
Caudal fin (Tail fin): At the end of the body, provides propulsion.

Common tail fin shapes include:

Forked: Deeply notched, like a ‘V’. Example: Mackerel.
Rounded: Smooth, convex curve. Example: Tilapia.
Truncate: Straight or nearly straight edge. Example: Some types of freshwater fish.
Lunate: Crescent-shaped, similar to forked but more rigid. Example: Tuna (not typically culturable, but a good example for shape).

General Body Shape

The overall body shape of a fish is an adaptation to its environment and lifestyle, particularly its swimming style.

Some common body shapes are:

Fusiform (Streamlined): Torpedo-shaped, tapering at both ends. Designed for fast swimming in open water. Example: Mackerel.
Compressed (Laterally flattened): Flat from side to side. Common in fish that live in dense vegetation or coral reefs, allowing for quick turns. Example: Tilapia.
Depressed (Dorso-ventrally flattened): Flat from top to bottom. Common in bottom-dwelling fish. Example: Rays (not culturable, but a good example).
Anguilliform (Eel-like): Elongated, snake-like body. Suitable for navigating through tight spaces or burrowing. Example: Eels, Catfish.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils, reviews the previous lesson briefly, and then introduces the new topic by asking pupils to name different types of fish they know and to describe any differences they notice between them.
Pupils’ Activity: Pupils respond to the teacher’s questions and share their observations.
Learning Point: Pupils are engaged and their prior knowledge is activated, linking to the new lesson.

Step 2: Presentation of Scales

Time: 7 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains the concept of scales and their importance. Using charts and specimens (if available), the teacher demonstrates the difference between scaled fish (e.g., Tilapia) and scaleless fish (e.g., Catfish).
Pupils’ Activity: Pupils observe the charts and specimens, ask questions, and take notes.
Learning Point: Pupils understand the presence or absence of scales as a distinguishing characteristic.

Step 3: Presentation of Mouth Shapes

Time: 7 minutes
Teaching Skill: Visualisation/Explanation
Teacher’s Activity: The teacher displays charts showing different fish mouth shapes (terminal, superior, inferior) and explains how each shape relates to feeding habits. The teacher uses examples of culturable fish.
Pupils’ Activity: Pupils identify and describe different mouth shapes from the visuals and discuss their possible functions.
Learning Point: Pupils learn to identify fish based on their mouth shapes and understand the connection to feeding.

Step 4: Presentation of Tail and Fins

Time: 7 minutes
Teaching Skill: Illustration/Description
Teacher’s Activity: The teacher uses diagrams and specimens to show the various types of fins and different tail fin shapes (forked, rounded, truncate). The teacher explains the function of each fin.
Pupils’ Activity: Pupils observe the fins and tails, differentiate their shapes, and understand their roles in movement and stability.
Learning Point: Pupils can distinguish fish based on their fin and tail characteristics.

Step 5: Presentation of General Body Shape

Time: 7 minutes
Teaching Skill: Classification/Comparison
Teacher’s Activity: The teacher presents various general body shapes of fish (fusiform, compressed, anguilliform) using images and describes how each shape is adapted to the fish’s environment and swimming style.
Pupils’ Activity: Pupils compare and contrast the different body shapes and identify examples of fish for each shape.
Learning Point: Pupils understand how overall body shape helps in identifying fish species and indicates their lifestyle.

Step 6: Comparative Analysis

Time: 5 minutes
Teaching Skill: Discussion/Application
Teacher’s Activity: The teacher guides a discussion where pupils compare two or three common culturable fish species (e.g., Tilapia and Catfish) based on all the characteristics discussed (scales, mouth, fins, body shape).
Pupils’ Activity: Pupils actively participate, listing the characteristics of each fish and highlighting their differences and similarities.
Learning Point: Pupils apply their knowledge to differentiate between actual fish species.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Mention two examples of scaled fish and two examples of scaleless fish.
Describe two different shapes of fish mouths and state one fish species for each.
List three types of fins found on a fish and state the primary function of the caudal fin.
Explain what is meant by a “fusiform” body shape and name a fish with this shape.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teaching Skill: Summarisation
Teacher’s Activity: The teacher summarises the key characteristics discussed in the lesson and assigns homework: “Draw and label a fish, indicating its scales (if present), mouth type, and fin types.”
Pupils’ Activity: Pupils listen to the summary and copy the homework assignment.
Learning Point: The lesson is concluded with a recap and a task to reinforce learning.

Lesson Keywords

Scales – Small, rigid plates covering the skin of some fish, providing protection.
Scaleless – Fish that do not have scales on their body.
Terminal mouth – A mouth located at the front tip of the head, pointing forward.
Inferior mouth – A mouth located on the underside of the head, pointing downwards.
Superior mouth – A mouth located at the top of the head, pointing upwards.
Fins – Appendages used by fish for swimming, balance, and steering.
Caudal fin – The tail fin of a fish, used for propulsion.
Fusiform – A streamlined, torpedo-like body shape, common in fast-swimming fish.
Compressed – A body shape that is flattened from side to side.
Anguilliform – An elongated, eel-like body shape.

Differentiation

The teacher will provide additional visual aids and simplified explanations for pupils who require more support. Advanced learners will be encouraged to research and identify more characteristics of specific fish species beyond those discussed.

Note for teachers using this lesson plan

Teachers should adapt the lesson plan to suit the specific needs and context of their pupils and available resources. Practical demonstrations with live or preserved specimens are highly recommended where possible to enhance learning.