Systematics, Biogeography and Functional Morphology of the Box (Family )

Thesis submitted by ORPHA BELLWOOD BSMT (Silliman, Phil.), MSc MarBiol (JCU) in November 2002

for the degree of Doctor of Philosophy in Marine Biology within the School of Marine Biology and Aquaculture James Cook University STATEMENT OF ACCESS

I, the undersigned, the author of this thesis, understand that James Cook University will make it available for use within the University Library and, by microfilm or other means, allow access to users in other approved libraries. All users consulting this thesis will have to sign the following statement:

In consulting this thesis I agree not to copy or closelyparaphrase it in whole or in part without the written consent of the author; and to make proper public written acknowledgmentfor any assistance which I have obtained from it.

Beyond this, I do not wish to place any restriction on access to this thesis.

/02 ...... V...... \...... 15/11 Orpha Be1 wood Date DECLARATION OF SOURCES

I declare that this thesis is my own work and has not been submitted in any form for another degree or diploma at any university or other institution or tertiary education. Information derived from the published or unpublished work of others has been acknowledged in the text and a list of references is given.

...... ~5 /11/02 0rpha B kllwood Date ABSTRACT

The box crabs (family Calappidae, H. Milne Edwards 1837) are a morphologically and ecologically distinctive group of marine crabs found in tropical and subtropical regions of the world. Traditionally placed in the section Oxystomata because of their characteristic triangular buccal frame (the 'oxystomatous' condition), they are one of the few brachyuran families capable of burying completely in soft substrata.

This study aims to review the systematics of the family and to examine the phylogenetic and functional implications of the oxystomatous condition in an evolutionary and biogeographic framework.

The systematic status of the family Calappidae and the phylogenetic relationships of its four component subfamilies were re-evaluated based on a cladistic analysis of 78 adult morphological characters. A single tree was produced (CI = 0.654, RCI= 0.403).

The monophyly of the Calappidae sensu lato is rejected. Yet the monophyly of each subfamily is supported, with the Calappinae clearly defined by 13 autapomorphies and the

Matutinae and Orithyiinae well-defined by 6 and 5 autoapomorphies. respectively. Only the Hepatinae appears to be a relatively weakly-defined taxon supported by 1 autapomorphy. The data also suggest that the Calappinae and Hepatinae form a single lineage which is closer to some xanthids than to the Matutinae or Orithyiinae. A close link between the Matutinae and some leucosiids and between the Orithyiinae and some dorippids is also apparent, with a suggestion that these four taxa all belong to a single lineage. A revised classification of the Oxystomata emend. and Calappidae sensu strict0 is proposed.

iii The phylogenetic relationships of 8 genera within the Calappidae sensu strict0 were further examined based on a cladistic analysis of 55 adult morphological characters. A single tree was produced (CF0.833, RCI=0.717). The data revealed two major lineages within the Calappidae: the 'calappine' clade consisting of ,

Cryptosoma, Cycloes, Paracyclois and Cyclozodion, and the 'mursiine' clade consisting of Acanthocarpus, Mursia and Platymera. Analyses of the fossil record and biogeographic patterns point to vicariance events associated with Gondwanan fragmentation. The earliest fossil record of the group suggest that present-day genera were already established by the Oligocene. Optimization of depth distributions on the cladogram indicates that the family initially diversified in deep water. Of the 10 genera, only three have a significant proportion of species recorded in waters less than 50 m:

Calappa, Cycloes and Cryptosoma. All three genera comprise a single crown-group clade. The remaining genera are largely restricted to water between 100 and 300m deep.

This suggests that the family had deep-water origins with only a single, derived, lineage moving into shallow waters.

An evaluation of existing evidence reveals two distinct means of concealment within the substratum in Brachyura: burrowing and burying. There are fundamental differences between the two types of behaviour, both in terms of ecological, mechanical and physiological implications. The oxystomatous condition was found to be primarily associated with burying crabs. The functional basis of the oxystomatous condition and its role in the burying habit was evaluated, based on two distinct forms within the

Calappidae sensu lato: Calappa and Matuta. Although the morphology of the respiratory system of both taxa follow the typical brachyuran pattern, Calappa and

Matuta both possess two unusual modifications which appear to be associated with their burying habit: accessory inhalant channels and elongate exhalant channels. Video analyses demonstrated that both taxa enter the substratum backwards, within seconds, at relatively steep angles. Both taxa are capable of burying completely within the substratum for extended periods of time while maintaining contact with overlaying water at the surface. Matuta is unusual in that it is also capable of complete deep burial. Dye tracer studies show that ventilation patterns in both taxa are broadly similar and confirm the function of the accessory inhalant channels as the primary inhalant pathway. Both

Calappa and Matuta ventilate their branchial chambers in the normal forward pattern and do not rely on prolonged reversed ventilation even when buried under the sediment. This is unique within Brachyura and is found only in one other family, the Leucosiidae, another oxystomatous group also characterized by accessory inhalant channels. It is hypothesized that the role of the oxystomatous configuration of the exhalant channels enhances the efficiency of the accessory inhalant channels. It serves to separate the inhalant and exhalant currents by dispersing the exhalant stream with sufficient force so as to prevent re-mixing, as well as creating a suction effect via the Bernoulli principle which facilitates the movement of fresh oxygenated water into the vicinity of the inhalant openings.

In summary, this study demonstrates that the Calappidae sensu lato is not a monophyletic, natural, group and that component taxa exhibit a clear evidence of convergent evolution. The oxystomatous condition, on which traditional groupings have long been based, has no phylogenetic basis and appears to have arisen independently in a number of lineages. In most lineages, however, the evolution of the oxystomatous condition appears to be closely associated with respiration whilst buried in soft substrata.

The oxystomatous condition therefore is a functional not a systematic characteristic. ACKNOWLEDGEMENTS

This PhD thesis has been undertaken on a part-time basis over a number of years and bears witness to the support, guidance and encouragement of many people who have seen me through those years.

First and foremost I wish to thank my supervisor, Associate Professor Chris Alexander for his unfailing support and guidance throughout the duration of this thesis. Supervising a part-time thesis such as this requires enduring patience, boundless stamina and cheerful optimism -thank you so much Alex for having these three qualities in great abundance. I owe my career to you -thank you for introducing me to their fascinating world

- from that first day when we seined the surf at Pallarenda Beach almost 20 years ago, your enthusiasm for these creatures has been infectious! Many thanks too for the SEM introduction and for teaching me the tricks of the trade of academic mentoring. It was great to learn from a master.

I am also extremely grateful to my colleagues in the crustacean world for their kind advice and encouragement. In particular, Mme Danielle Guinot (Museum National dYHistoireNaturelle, Paris), who inspired me to work on the phylogeny of brachyurans. Her advice in the early years of this thesis was invaluable; Richard Hartnoll (University of Liverpool Marine Laboratory, UK), for stimulating discussions and encouragement to look at the broader aspects of brachyuran biology; Paul Clark and Geoff Boxshall (Natural History Museum, London), for great company and wonderful insights into the world of Crustacea; Nguyen Ngoc Ho and Marcus Tavares (Museum National d'Histoire Naturelle, Paris), for stimulating discussions and valuable comments on some of the manuscripts from this thesis; Peter Davie (Queensland Museum, Brisbane), Di Jones (Western Australian Museum, Perth) and Peter Ng (Zoological Museum, University of Singapore), for helpful advice and for pointing me in the right direction and to the right people in the early years of this thesis; Belia Galil (National Institute of Oceanography, Israel), for graciously sharing the calappid corner in crustacean research and for those hard-to-find taxonomic references; Gerhard Scholtz (University of Berlin) and Fred Schram (University of Amsterdam), for championing the cause of crustacean phylogenetic systematics and for helpful advice on the broader issues of evolutionary biogeography; and Trisha Spears (Florida State University, Tallahassee, Florida), for providing the molecular perspective in brachyuran systematics. Her enthusiasm and optimism has kept me going all these years.

Financial support from a James Cook University Doctoral Merit Research Scheme grant and a Women in Research Encouragement Award were both timely and much appreciated. The Crustacean Society Best Student Paper Award was also a great boost to the spirit and kept me going through a rough patch.

This project would not have been possible without access to museum collections. I am deeply indebted to the following people for their kindness in letting me examine and dissect the valuable specimens in their care: Dr. Peter Arnold (Museum of Tropical Queensland, Townsville), Dr. Peter Davie (Queensland Museum, Brisbane), Mme. Danielle Guinot (Museum National d7HistoireNaturelle, Paris), Paul Clark (The Natural History Museum, London), Dr. Ray Manning (Smithsonian Museum, USA), Dr. Peter Ng (Zoological Museum, University of Singapore). Many thanks also to Julian Hughes, Phil Osmond, Jane Webb, Dave Bellwood, John Collins, Vachira Lheknim and Mike Steer for the donation of crabs. I'm sorry that the suggestion that calappids are so gentle that you can pop them down your swimming trunks turned out to be untrue.

The following wonderful people helped me in ways that may have appeared small at the time but contributed more than one can imagine. My sincere thanks to: Peter Ridd and Richard Rowe, for helpful advise on the physics behind functional morphology; Peter Forey (Natural History Museum, London), for his patience in showing me the fossil calappids even though they are not fishes;

vii Howard Choat who recognised that 14 years of teaching and administration would never help in academia and insisted that I start this PhD; Andy Hoey for watching the captive crabs when time was short; Michael Marnane for advice on aquarium maintenance; Jenny MacGregor, for her administrative sense and for keeping an eye on the ball for me; the Biological Sciences technical staff, especially Greg, Jane, Colleen and Janice, for helping me with access to equipment and cheerfully indulging my weird requests of bits; Di McNamara, for help with printing and access to the colour photocopier and turning a blind eye when I use too much paper; Leigh Winsor, Fay Kristides and Gilianne Brodie for sharing the part-time PhD blues; and Alistair Birtles for stretching the PhD envelope and making room for the rest of us.

And finally, to the B-team: Oliver, Hannah and David - thank you so much for being there, you have kept me sane through all these years. This thesis is for you. Kids, this is why mum falls asleep during The Simpsons! TABLE OF CONTENTS

Page Statement of Access ...... i Declaration of Sources ...... ii ... Abstract ...... zzz Acknowledgements ...... vi Table of Contents ...... ix List of Figures ...... xi . . List of Tables ...... xzz

Chapter 1 : General Introduction 1.1 Introduction and Aims ...... 1 1.2 Overview of the biology of the Calappidae ...... 4 1.3 Thesis Structure ...... 6

Chapter 2: The Familial Status of the Calappidae sensu lato: A Phylogenetic Appraisal (Published in Zool . J. Linn . Soc. 118: 165-193) 2.1 Introduction ...... 8 2.2 Historical Review 2.2.1 The Calappidae ...... 9 2.2.2 The Oxystomata ...... 11 2.3 Materials and Methods 2.3.1 Selection of taxa and outgroups ...... 12 2.3.2 Character selection and coding ...... 13 2.3.3 Phylogenetic analysis ...... 18 2.4 Comparative Morphology 2.4.1 Antennule and antennae ...... 18 2.4.2 Orbital region ...... 19 2.4.3 Antero-ventral region ...... 2 1 2.4.4 Pereiopods ...... 21 2.4.5 Abdomen ...... 26 2.4.6 Carapace ...... 28 2.4.7 Sternum ...... 28 2.4.8 Mouthparts ...... 31 2.4.9 Endostome ...... 37 2.4.10 Male reproductive structures ...... 38 2.4.1 1 Female reproductive structures ...... 40 2.5 Results ...... 40 2.6 Discussion ...... -45

Chapter 3: Phylogeny and Evolutionary Biogeography of the Calappidae sensu strict0 (Published inJ. Zool., Lond . 244:459-471) 3.1 Introduction ...... 52 3.2 Materials and Methods ...... 52 3.2.1 Phylogenetic analyses ...... -53 3.2.2 Analyses of biogeographic and depth record ...... 57 3.3 Comparative Morphology ...... 57 3.3.1 Carapace and anterior regions ...... 58 3.3.2 Antennule and antennae ...... 59 3.3-3 1 maxilliped ...... 59 3.3.4 2nd maxilliped ...... 60 3.3.5 3rd maxilliped ...... 60 3.3.6 Cheliped ...... 61 3.3.7 Other pereiopods ...... 63 3.3.8 Sternum ...... 63 3.3.9 Abdomen ...... 64 3.3.10 Reproductive structures...... -64 3.4 Results ...... 65 3.5 Discussion 3.5.1 Phylogeny and classification ...... 69 3 .5.2 Fossil record and historical biogeography ...... 71 3.5.3 Biogeography ...... 74 3.5.4 Depth distributions ...... 79

Chapter 4: Functional significance of the oxystomatons condition: A comparative study of the respiratory structures and burying behaviour of Calappa and Matuta (Section 1. Published in J. Nat.Hist. 36: 1223-1238)

4.1 Introduction ...... -82 4.2 Section 1 - A review of the occurrence of the burying behaviour in brachyuran crabs ...... 84 4.2.1 A survey of families ...... 87 4.2.2 Biological basis and consequences of burying ...... 92 4.2.3 Morphological adaptations to burying ...... 97 4.2.4 Physiological limitations of burying ...... 98 4.2.5 Synthesis ...... 10 1 4.3 Section 2 - A morphological study of respiratory structures in oxystomatous crabs and analysis of the burying behaviour and respiratory currents in Calappa hepatica and Matuta lunaris ...... 105 4.3.1 Materials and methods ...... 106 4.3.2 Results 4.3.2.1 Comparative anatomy ...... 111 4.3.2.2 Functional predictions ...... 120 4.3.2.3 Experimental evaluation ...... 124 4.5 Discussion ...... 133

Chapter 5: General Discussion ...... 140

References ...... 145

Appendices ...... 157 LIST OF FIGURES

Figure Page 1.1 Representative species from each of the four subfamilies in the Calappidae ...... 2

2.1 Proximal articulations of the cheliped ...... 23

2.2 The sternum ...... 30

2.3 Ventral aspect of the third maxilliped ...... 33

2.4 Cladogram of the relationships of the 4 subfamilies in the Calappidae sensu lato and 4 outgroup taxa ...... 41

3.1 Cladogram of the relationships of the eight genera within the Calappidae sensu strict0 ...... 66

3.2 Distribution records of Cyptosoma and Cycloes ...... 75

3.3 Distribution records of Acanthocarpus. Mursia and Platymera ...... 76

3.4 Distribution records of Paracyclois and Cyclozodion ...... 78

3.5 Depth distribution of calappid genera ...... 80

3.6 Cladogram of depth distribution within the Calappidae ...... 81

4.1 Putative brachyuran phylogeny showing the families where burying behaviour is reported ...... 86

4.2 Variations in the mechanics of the burying behaviour ...... 94

4.3 Methodology used in measuring burial depth ...... 108

4.4 Methodology used for visualising respiratory currents in buried crabs ..... 110

4.5 External respiratory morphology of Atergatis floridus Matuta lunaris and Calappa hepatica ...... 112

4.6 SEM of setae along the inhalant pathway in Matuta lunaris ...... 115

4.7 Relative positions of the exhalant and inhalant pathways ...... 117

4.8 SEM of setae along the inhalant pathway in Calappa hepatica ...... 119

4.9 Predicted ventilation patterns in Matuta lunaris and Calappa hepatica .... 121

4.10 Effective burial depth of Matuta lunaris and Calappa hepatica ...... 126

4.1 1 Patterns of burial in Matuta lunaris and Calappa hepatica ...... 127 LIST OF TABLES

Table Page

2.1 List of characters used in the phylogenetic analysis of 4 subfamilies of the Calappidae sensu lato and 4 outgroup taxa ...... 14

2.2 Character matrix used in the cladistic analysis of the Calappidae ...... 17

2.3 Traditional characters used for defining the family Calappidae...... 46

3.1 List of characters used in the phylogenetic analysis of the 8 genera in the Calappidae sensu stricto and 2 outgroup taxa ...... 54

3.2 Character matrix used in the cladistic analysis of the Calappidae sensu stricto ...... 56

4.1 Summary of published information on aspects of burying in brachyuran crabs...... 88

4.2 Summary of characteristics associated with burying vs. burrowing ...... I02

4.3 Realized ventilation patterns in Matuta lunavis and Calappa hepatica.. .. .13 0

LIST OF APPENDICES

Appendix I List of material examined ...... 157

Appendix I1 Particle size composition of substrata used in this study ...... I59

Appendix I11 Traditional classification of the Calappidae...... 160

Appendix I1 Proposed classification of oxystomatoid crabs ...... 161

Appendix V Reprints of publications arising from this thesis A Bellwood (1 996) B Bellwood (1998) C Bellwood (2002)

xii