Marine Mussels

Ecology, Physiology, Genetics and Culture

Elizabeth Gosling

• Publisher: Wiley
• Year: 2021
• ISBN:
  9781119293934
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Fisheries & Aquaculture
• Index: Technology & Engineering

A comprehensive volume providing broad and detailed coverage of marine mussels

Marine Mussels: Ecology, Physiology, Genetics and Culture provides readers with in-depth, fully up-to-date information on all major aspects of marine mussels. Written by an internationally renowned expert in the field, this authoritative volume addresses morphology, ecology, ­feeding, phylogeny and evolution, reproduction and larval development, settlement and recruitment, genetics, disease, management of culture systems and more. The book encompasses many different species of marine mussels: genus Mytilus, other important commercial marine genera such as Perna, Aulacomya and Choromytilus, and non-commercial genera including Modiolus, Geukensia, Brachidontes and hydrothermal vent Bathymodiolus.

Comprising twelve extensively cross-referenced chapters, the book discusses a diversity of integrated topics that range from fundamental physiology of marine mussels to new techniques being applied in their biology and ecology. Author Elizabeth Gosling reviews contemporary developments and issues in the field such as the use of DNA genetic markers in detecting and diagnosing different strains of pathogenic bacteria, the use of mussels as monitors of marine contaminants, sophisticated modelling techniques that simulate disease and forecast outbreaks, and the impacts of global warming, ocean acidification and hypoxia on marine mussels. Presenting an inclusive, highly detailed treatment of mussel biology, physiology, genetics, and culture, this invaluable resource:

• Contains thorough descriptions of external and internal anatomy, global and local distribution patterns, the impacts of mussels on marine ecosystems, and the processes of circulation, respiration, excretion and osmoregulation
• Reflects significant advances in mussel science and new areas of research in marine mussels
• Describes the fundamentals of mussel aquaculture, the types and levels of contaminants in the marine environment and new approaches for sustainable aquaculture development
• Discusses the application of genetic methods, population genetics, global breeding programmes and the emerging area of bivalve genomics
• Addresses the role of mussels in disease transmission to humans, including production and processing controls, regulation of monitoring and quality control

Marine Mussels: Ecology, Physiology, Genetics and Culture is essential reading for biological scientists, researchers, instructors and advanced students in the fields of biology, ecology, aquaculture, environmental science, toxicology, genetics, pathology, taxonomy and public health.

1
Phylogeny and Evolution of Marine Mussels

Introduction

The phylum Mollusca is the second largest phylum of animals, with about 130 000 named extant species and 70 000 described fossil species (Haszprunar et al. 2008). While most of these are marine, many live in freshwater and terrestrial habitats. Research has indicated that molluscs had a terminal Precambrian origin, with rapid divergence occurring in the Cambrian era some 540–560 million years ago (Stöger et al. 2013). All molluscs have a soft body that, with the exception of some groups (see later), is protected by a hard calcium shell. Inside the shell is a heavy fold of tissue called the mantle that encloses the internal organs of the animal. Another feature of the phylum is a large muscular foot that is generally used for locomotion. Although most molluscs share this basic body plan, the group is characterised by a great diversity of form and habit.

Phylogeny of the Phylum Mollusca

Eight living classes (lineages) of molluscs have been recognised, primarily based on clad¹ (phylogenetic) analysis of morphological characters (Haszprunar et al. 2008). Aplacopora incorporates two classes, Solenogastres and Caudofoveata; these are worm‐shaped, deep‐water animals lacking a shell. Polyplacophora, often referred to as chitons, inhabit hard substrates on rocky shores and are characterised by eight dorsal shell plates. Aplacophora and Polyplacophora are grouped in the clade² Aculifera, which is regarded as monophyletic (i.e. all taxa in this group share a common ancestor) (Sigwart & Sutton 2007). The remaining five classes are grouped in the clade Conchifera, which is also regarded as a monophyletic group. Monoplacophora live in deep waters and are small and limpet‐like, with a single cap‐like shell. The class Bivalvia includes laterally compressed animals enclosed in two shell valves, such as clams mussels, oysters and scallops. Scaphopoda, commonly known as tusk shells, live in marine mud and sediments. The class Gastropoda is the largest and most diverse, containing spirally coiled snails, flat‐shelled limpets, shell‐less sea slugs and terrestrial snails and slugs. Octopus, squid and cuttlefish are in the class Cephalopoda and represent the largest, most organised and specialised of all the molluscs. The Monoplacophora are generally accepted as the earliest extant offshoot of the Conchifera (Haszprunar 2008).

Morphological disparity among the lineages has given rise to numerous conflicting phylogenetic hypotheses. Molecular investigations using nuclear ribosomal gene sequences (18S and 28S) offered little resolution (Ponder & Lindberg 2008). More recent studies, using phylogenomic‐scale molecular data sets (Kocot et al. 2011; Smith et al. 2011; Stöger et al. 2013), have significantly advanced understanding of molluscan phylogeny by providing well‐supported tree topologies and generally congruent results (Telford & Budd 2011; Kocot 2013; Schrödl & Stöger 2014). Probably the most important achievement of these studies is the establishment of the Aculifera and Conchifera groupings.

Several major evolutionary hypotheses and sister relationships have been proposed for the eight living molluscan classes, which are illustrated in Figure 1.1 (Sigwart & Lindberg 2015). Sigwart & Lindberg (2015) assembled a data set of 42 unique published trees describing molluscan interrelationships, which included at least five out of the eight classes. They found that almost 60% of trees based on morphological data (N = 27) were similar, while only 45% of those based on molecular data (N = 15) were similar; the distances separating morphological and molecular trees indicated that they were similar in almost 30% of pairs and different in 20%. It is interesting that there are no studies in which both molecular and morphological data have been simultaneously analysed for all eight classes of Mollusca (Sigwart & Lindberg 2015). Regarding some of the hypotheses illustrated in Figure 1.1, the authors found that support for Cyrtostoma or Diasoma was relatively weak, while the Serialia concept was deserving of due consideration (see also Stöger et al. 2013). They found no consensus support for the topology of the morphological Testaria concept. Integration of new molecular techniques with morphological and developmental data using multiple type species from all eight molluscan classes will no doubt continue to deepen our understanding of molluscan phylogeny and evolution (Kocot 2013; Sigwart & Lindberg 2015).

Figure 1.1 Schematic topology of the major evolutionary hypotheses and sister relationships proposed for the eight living classes in Mollusca: Aculifera (Solenogastres + Caudofoveata + Polyplacophora), Aplacophora (Caudofoveata + Solenogastres), Conchifera (Monoplacophora + Bivalvia + Scaphopoda + Gastropoda + Cephalopoda), Cyrtosoma (Gastropoda + Cephalopoda; historically also including Monoplacophora), Diasoma (Bivalvia + Scaphopoda), Serialia (Polyplacophora + Monoplacophora), and Testaria (Conchifera + Polyplacophora). Text in bold indicate the seve...