MORPHOMETRICS SPECIES

Morphometrics Species Distinction and Condition Factor of Oreochromis Niloticus and Hybrid

Table of Contents

Chapter One: 1.0 INTRODUCTION3

1.1 TAXONOMIC CLASSIFICATION3

1.1.1 AQUACULTURE IN JAMAICA5

1.1.2 CONDITION FACTOR8

1.2 RATIONALE9

1.3 OBJECTIVES11

1.4 LITERATURE REVIEW12

1.4.1 Introduction12

1.4.2 Distinguishing Characteristics12

1.4.3 Taxonomy13

Classification of species used in Aquaculture14

1.5 IMPORTANCE OF JAMAICA'S FISHING INDUSTRY15

1.6 MORPHOMETRIC OF TILAPIA16

1.7 SEX IDENTIFICATION22

1.8 MERISTIC TRAITS23

1.8.1 Application of Meristics24

1.9 ENVIRONMENTAL REQUIREMENTS26

CHAPTER TWO: SITE DESCRIPTION29

CHAPTER THREE: METHODOLOGY31

3.1 FIELD WORK31

3.2 LABORATORY WORK31

3.3 SEX DETERMINATION34

3.4 LENGTH-WEIGHT RELATIONSHIP34

CHAPTER FOUR: 4.0 RESULTS36

Dependent Variable - Body Depth134

Dependent Variable - Eye Diameter134

Eye diameter O. niloticus135

5.1 MORPHOMETRIC USED TO IDENTIFY Oreochromis niloticus AND HYBRID TILAPIA136

5.2 CONDITION FACTOR OF THE SPECIES137

5.3 MORPHOMETRIC RECORD OF Oreochromis niloticus AND HYBRID TILAPIA IN JAMAICA138

5.4 MORPHOMETRIC ANALYSIS OF SPECIES139

5.5 MORPHOMETRIC ANALYSIS BASED ON SEX140

5.6 ANALYSIS OF MORPHOMETRIC RATIOS FOR ALL INDIVIDUALS140

5.7 CONCLUSION141

REFERENCES162

Chapter One: 1.0 INTRODUCTION

Tilapia is the common name used for a variety of cichlid. From the genera Oreochromis, Sarotherodon, and Tilapia; and is similar to a taxonomic grouping known as the tilapiine cichlids. The expression Tilapia is derived from the African native Bechuana word “thiape” meaning fish. Tilapia inhabits a variety of fresh water systems e.g. ponds, rivers and lakes and, less commonly, brackish water habitats and estuaries. Where Tilapia has been deliberately or accidentally introduced into the above mentioned systems, they have often become problematic invasive species (Mississippi Museum of Natural Science, 2006).

1.1 TAXONOMIC CLASSIFICATION

The appropriate taxonomic distinction of 'species' provides an essential baseline that supports biological research (Last, 2007). The identification of members from the group of 'species' called Tilapia is problematic because of their morphological similarities and lack of research in this area.Historically, the morphology of fishes has been the primary source of information for taxonomic and evolutionary studies. There are several characters available for morphological study, which are most commonly divided into two categories: Morphometrics and meristic.

Most species of the tribe Tilapiani is now being used in aquaculture was grouped initially into one genus, Tilapia. The species within this genus were then classified according to differences in their mode of reproduction. Species which evolved into substrate spawners but protect their eggs were retained in the genus Tilapia, while those which orally rear their clutches were grouped into a new genus Sarotherodon. Classification of the three genera Tilapia, Sarotherodon and Oreochromis were based primarily on the differences in their breeding and feeding habits. (Lowe McConnel; 1959 Trewawas, 1973, 1978, 1982).

Scientific Classification

Kingdom: Animalia

Phylum: Chordata

Super class: Ostechthyes

Class: Actinopterygii (ray-finned fishes)

Order: Perciformes (perch-likes)

Family: Cichlidae

Sub family: Pseudocrenilabrinae

Genera: Oreochromis

The information used in developing and understanding of evolutionary relationships among fishes comes primarily from detailed taxonomic studies, particularly careful descriptions of species. Such studies are the foundation of ichthyology and are more necessary than ever, not only as a basis for evolutionary, ecological, and physiological studies but for conservation, as well. The basic methods used in taxonomic studies fall into six categories:

Morphometric measurements

Meristic traits

Anatomical characteristics

Color patterns

Karyotypes

Biochemical characteristics

Morphometrics is the” measurement of morphology" or form of an organism it is a scientific method used to quantify shape differences among organisms. Stock identification and assessment in Tilapia has been rapidly improved ...