Biodiversity and community structure of free- living marine nematodes from intertidal areas in the

257 Pages·2017·4.32 MB·English

Biodiversity and community structure of free-
living marine nematodes from intertidal areas
in the Persian Gulf
Narjes Sahraean

Biodiversity and community structure of free-
living marine nematodes from intertidal areas
in the Persian Gulf

Promoter: Prof. Dr. Tom Moens

Thesis submitted in partial fulfilment of the requirements for
the degree of Doctor in Science (Marine Sciences)
Academic year 2016-2017
Members of reading and examination committee

Prof. Dr. Ann Vanreusel (chair)
Ghent University, Belgium

Dr. Nele De Meester (secretary)
Ghent University, Biology Dept, Marine Biology

Prof. Dr. Koen Sabbe
Ghent University, Biology Dept.,
Laboratory for Protistology & Aquatic Ecology

Prof. Dr. Frederik Leliaert
Botanical Garden Meise, Belgium &
Ghent University, Biology Dept.

Prof. Dr. Helena Adão
University of Evora, Portugal

Prof. Dr. Giovanni dos Santos
Federal University of Pernambuco, Brazil

Prof. Dr. Tom Moens (promoter)
Ghent University, Belgium
Dedicated to:

Hadi, Parmida, Amirhossein, my parents and
Marianne for all their love and supports
Table of contents
Table of contents
ACKNOWLEDGMENTS I
SUMMARY IV
SAMENVATTING VIII
CHAPTER 1 GENERAL INTRODUCTION 3
1. STUDY AREA: THE PERSIAN GULF 5
1.1 Geographical, physical and climatological features 5
1.2 Geo-political and industrial importance 11
1.3 Marine Ecosystems of the Persian Gulf 12
1.4 Environmental threats to the Persian Gulf marine environment 16
General information 16
Environmental stressors 17
2 INTERTIDAL AREAS AND SANDY BEACHES 23
2.1 Intertidal areas 23
2.2 Sandy beaches: Definition, characteristics and classification 24
3 BENTHIC COMMUNITIES OF BEACHES 28
3.1 Definition, classification and ecological significance 28
3.2 Intertidal meiobenthos: abundance and diversity 29
3.3 Marine nematodes 30
3.3.1 General characteristics 30
3.3.2 Nematode biodiversity 31
3.3.3 Temporal and spatial patterns in marine nematode assemblages 32
3.4 Zonation patterns of intertidal meiofauna/nematodes 36
3.4.1 Horizontal zonation patterns 36
3.4.2 Vertical patterns 39
3.5. Nematode feeding strategies 41
.3.6 Functional roles of nematodes in ecosystems 43
.3.6.1 Roles in benthic food chains 44
3.6.2. Roles in microbial decomposition and nutrient cycling 45
3.7. Marine nematode dispersal and population genetics 46
3.8. Nematodes as bio-indicators 48
3.9. Diversity measures to monitor impact 50
3.10. Benthic fauna of the PG 52
4. RESEARCH AIMS AND OBJECTIVES 53
CHAPTER 2 NEMATODE ASSEMBLAGE STRUCTURE AND DIVERSITY IN INTERTIDAL
BEACHES OF THE NORTHERN PART OF THE STRAIT OF HORMUZ 59
1 INTRODUCTION 62
2 MATERIALS AND METHODS 64
2.1 Sampling sites and design 64
2.2 Sample collection, elutriation and analysis 65
2.3 Data analysis 67
3 RESULTS 69
3.1 Sediment granulometry and total element analysis 69
3.2 Nematode abundance and dominant genera 70
3.3 Nematode diversity 74
3.4 Nematode assemblage structure 77