Cephalopods of the Broad Caribbean: Distribution, abundance, and ecological importance

156 Pages·2015·5.84 MB·English

by  Heather L. Judkins

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Graduate Theses and Dissertations Graduate School
6-10-2009
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Heather L. Judkins
University of South Florida
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Importance" (2009). Graduate Theses and Dissertations.
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Cephalopods of the Broad Caribbean: Distribution, Abundance, and Ecological

Importance

by

Heather L. Judkins

A dissertation submitted in partial fulfillment
of the requirements for the degree of
Doctor of Philosophy
College of Marine Science
University of South Florida

Co-Major Professor: Joseph Torres, Ph.D.
Co-Major Professor: Michael Vecchione, Ph.D.
Susan Bell, Ph.D.
David Mann, Ph.D.
Mark Luther, Ph.D.

Date of Approval:
June 10, 2009

Keywords: mollusca, Caribbean diversity, biogeography, latitudinal gradients, coastal
Atlantic Ocean

©Copyright 2009, Heather L. Judkins
ACKNOWLEDGEMENTS

I would like to acknowledge the team of people who have helped me through this
process. Dr. Joseph Torres, Dr. Michael Vecchione, and my entire committee, Dr. Susan
Bell, Dr. David Mann, and Dr. Mark Luther, have been instrumental in terms of advice,
pathways to follow, and excellent sounding boards for my many questions. I would like
to acknowledge Dr. Clyde Roper for his foresight in seeing that I had potential to add a
small part of research to the cephalopod scientific community and his words of wisdom
and encouragement throughout this entire venture. I would like to thank Dr. Nancy Voss
for her advice and guidance in understanding of cephalopod species of the Broad
Caribbean. Her assistance in my work is beyond compare. Dr. Ronald B. Toll and Dr.
Steven C. Hess were instrumental in documenting cephalopod specimen information
from the Hourglass Cruises that were conducted from 1965 through 1967, by the Marine
Research Laboratory of the Florida Board of Conservation on the continental shelf of the
Gulf of Mexico which was included in my dissertation. I also thank Teresa Greely and
Angela Lodge for their assistance throughout the two years of my GK12 Oceans
Fellowship and the opportunity to coordinate the regional competition for the National
Ocean Sciences Bowl that I have been so excited to be a part of for the College of Marine
Science at USF. Lastly, I wouldn’t be where I am without the unfailing support and
constant source of smiles from my family and friends who have been there through the
ups and downs of my journey. Thank you.
TABLE OF CONTENTS

TABLE OF CONTENTS i

LIST OF TABLES iii

LIST OF FIGURES iv

ABSTRACT v

CHAPTER 1. INTRODUCTION 1
1.1 Broad Caribbean 1
1.2 Cephalopod Biology 3
1.3 Distribution of Cephalopods 4
1.4 Abundance of Cephalopods 4
1.5 Cephalopods in Food Webs 5
1.6 Overall Significance 7
1.7 Study Goals 8
1.8. Study Area 9
1.9 Materials and Methods 9
1.10 References 13

CHAPTER 2. BIOGEOGRAPHY OF CEPHALOPODS OF THE BROAD
CARIBBEAN 16
2.1 Introduction 16
Broad Caribbean 16
The Cephalopods 18
Biogeography of Cephalopods 18
Abundance of Cephalopods 21
Ecological Focus 21
Study Area 24
2.2 Materials and Methods 24
Statistical analysis 26
2.3 Results 27
Rapoport’s Rule and Species Richness 27
Cephalopod Biogeography 28
Distribution and Abundance 29
Range Extensions 29
New Species to Area 38
2.4 Discussion 38
Rapoport’s Rule and Species Richness 38
Cephalopod Biogeography 41
i
Distribution and Abundance 43
Range Extensions 45
New Species 45
2.5 References 47

CHAPTER 3. CEPHALOPODA (MOLLUSCA: CEPHALOPODA) OF THE
GULF OF MEXICO 52
3.1 Introduction 52
3.2 Major Systematic Revisions 56
3.3 Comparative Assessment of the Group in the Gulf of Mexico 56
3.4 Explanation of Checklist 57
3.5 Acknowledgements 60
3.6 References 61
3.7 Gulf of Mexico Checklist 66
3.8 Taxonomic Summary for Cephalopods of the Gulf of Mexico 73

CHAPTER 4. FIRST RECORDS OF Asperoteuthis acanthoderma (Lu, 1977)
(CEPHALOPODA: OEGOPSIDA: CHIROTEUTHIDAE) FROM THE
NORTH ATLANTIC OCEAN; STRAITS OF FLORIDA 74
4.1 Abstract 74
4.2 Introduction 75
4.3 Systematics 76
4.4 Description 76
4.5 Discussion 81
4.6 Acknowledgements 86
4.7 References 87
4.8 Figure Legends 88

CHAPTER 5. CONCLUSIONS 94
5.1 Summary 94
5.2 References 100

APPENDICES 102
Appendix A: Regional distribution point coordinates 103
Appendix B: Species richness comparison quadrats 104
Appendix C: Cephalopod distribution maps 105

ABOUT THE AUTHOR End page
ii
LIST OF TABLES
Table 2.1 Regional cephalopod locations 20
Table 2.2 Region, species number and sample number for hotspots 33
Table 2.3 Cephalopod range extensions to Broad Caribbean 35
Table 3.1 Checklist of the Cephalopods of the Gulf of Mexico 66
Table 3.2 Taxonomic summary for cephalopods of the Gulf of Mexico 73
Table 4.1 Measurements of Asperoteuthis acanthoderma specimens 89
Table 5.1 Gulf of Mexico checklist species not included in Ch. II 95

iii
LIST OF FIGURES
Figure 1.1 Current flow through the Caribbean Sea and Gulf of Mexico 2
Figure 1.2 A summary of the role of cephalopods in the world’s oceans 6

Figure 1.3 Study Area 9

Figure 2.1 Current flow through the Caribbean Sea and Gulf of Mexico 17
Figure 2.2 Study area 24
Figure 2.3 Species richness per 5˚ latitudinal band 30
Figure 2.4 Comparison of species richness and number of individuals 30
Figure 2.5 Rapoport’s Rule- Rarefaction curve 31

Figure 2.6 Rapoport’s Rule- Chao 1 estimator graph 31

Figure 2.7 Eight study sites for richness and diversity comparisons 32

Figure 2.8 Species richness regional comparison 32

Figure 2.9 Hotspot species observed- Rarefaction curve 33

Figure 2.10 Hotspot Chao 1 estimator of regional species richness 34

Figure 2.11 Broad Caribbean sample effort map 34

Figure 4.1 Key West Asperoteuthis acanthoderma specimen 91

Figure 4.2 Marathon Asperoteuthis acanthoderma specimen 92

Figure 4.3 Internal organs of the Key West specimen 93

iv
CEPHALOPODS OF THE BROAD CARIBBEAN SEA: DISTRIBUTION,
ABUNDANCE, AND ECOLOGICAL IMPORTANCE

Heather L. Judkins
ABSTRACT
The Broad Caribbean region is defined as the Gulf of Mexico, and the coastal and
marine areas of the Caribbean Sea, including the chain of islands forming the Greater and
Lesser Antilles, Turks and Caicos, the Bahamas, and the gulf coasts of the United States,
Central and South America (Stanley, 1995). The cephalopods of the Broad Caribbean
were examined in terms of distribution, abundance, and ecological importance. A suite
of 5190 preserved cephalopod specimens were identified and catalogued to produce
regional maps of cephalopod distribution within the Broad Caribbean. Eighteen range
extensions were noted for known species. Regional species richness was examined with
respect to Rapoport’s Rule with an eye toward possible cephalopod hotspots in the
region. Cephalopods of the Broad Caribbean within the latitudinal bands of 8˚N and
30˚N do not support Rapoport’s Rule as they exhibit increasing species richness with
increasing latitude. Eight subareas were chosen to compare species richness. Regionally,
species richness is patchy, with the largest concentration of cephalopods off the eastern
Florida coast. Areas of the southern Caribbean Sea are in need of more samples for
accurate assemblage counts and more meaningful comparisons with other Caribbean
regions. Rarefaction curves were used to normalize the variously sized samples
throughout the Broad Caribbean. A checklist of the Gulf of Mexico based on literature
developed a picture for the northern regions of the Broad Caribbean. This checklist
v
provided an updated account of cephalopod species that were reported from smaller
literature works. Lastly, the first observation in the North Atlantic Ocean of the deep-sea
squid Asperoteuthis acanthoderma (family Chiroteuthidae) was described. The
description is based on two nearly intact, but damaged, specimens that were found
floating at the surface in the waters off Key West and Marathon, Florida in 2007. All
previously known records are recorded from a few specimens scattered in the western
Pacific Ocean. There is a need for increased sampling throughout the Broad Caribbean to
explore the systematics, life histories, distribution patterns, and potential fisheries for this
group of organisms.

vi
CHAPTER 1
INTRODUCTION

Cephalopods of the Broad Caribbean have not been reviewed in recent years. The
unique features, currents, and coastlines of the Gulf of Mexico, Caribbean and the Straits
of Florida combine as a potentially unique ecotone for cephalopod distribution,
abundance, and diversity. Work conducted by G. Voss (1956), C.F. Roper (1984), N.
Voss (1998), M. Vecchione (2002), and others provide background for further
exploration of cephalopods in this area. The present study focuses on over 5000
specimens collected from the area to extend cephalopod research.
1.1 The Broad Caribbean
The Broad Caribbean region is defined as the Gulf of Mexico, and the coastal and
marine areas of the Caribbean Sea, including the chain of islands forming the Greater and
Lesser Antilles, Turks and Caicos, the Bahamas, and the Gulf coasts of North, Central
and South America (Stanley, 1995).
The region is influenced by waters that flow through the lower Caribbean islands,
originating from the Guiana Current that moves north along Brazil’s coast. The Guiana
Current is joined by the North Equatorial Current, which flows through the lower
Caribbean, veering north around western Cuba and into the Gulf of Mexico. Some
upwelling occurs along the southern region of the Caribbean Sea (Longhurst, 1998). The
majority of the flow moves around the Gulf coasts of the United States, flowing down
along the west Florida coast before moving through the Straits of Florida to become the
1