Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Nematode Parasites of Vertebrates: Their Development and Transmission

DURING this year I have so often been asked how this Code could be obtained that I hasten, with your permission, to announce that the Washington Biological Society has just published a reprint at the price of one dollar. Prof. C. W. Stiles, secretary to the Commission, says: “I would suggest that, if your colleagues wish copies, it would expedite matters to order a number at once”. The address of the Society is at the Bureau of Entomology, Washington, D.C., U.S.A.

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International Code of Zoological Nomenclature

More than 60 marine non-indigenous species (NIS) have been removed from previous lists and 84 species have been added, bringing the total to 986 alien species in the Mediterranean [775 in the eastern Mediterranean (EMED), 249 in the central Mediterranean (CMED), 190 in the Adriatic Sea (ADRIA) and 308 in the western Mediterranean (WMED)]. There were 48 new entries since 2011 which can be interpreted as approximately one new entry every two weeks. The number of alien species continues to increase, by 2-3 species per year for macrophytes, molluscs and polychaetes, 3-4 species per year for crustaceans, and 6 species per year for fish. The dominant group among alien species is molluscs (with 215 species), followed by crustaceans (159) and polychaetes (132). Macrophytes are the leading group of NIS in the ADRIA and the WMED, reaching 26-30% of all aliens, whereas in the EMED they barely constitute 10% of the introductions. In the EMED, molluscs are the most species-rich group, followed by crustaceans, fish and polychaetes. More than half (54%) of the marine alien species in the Mediterranean were probably introduced by corridors (mainly Suez). Shipping is blamed directly for the introduction of only 12 species, whereas it is assumed to be the most likely pathway of introduction (via ballasts or fouling) of another 300 species. For approximately 100 species shipping is a probable pathway along with the Suez Canal and/or aquaculture. Approximately 20 species have been introduced with certainty via aquaculture, while >50 species (mostly macroalgae), occurring in the vicinity of oyster farms, are assumed to be introduced accidentally as contaminants of imported species. A total of 18 species are assumed to have been introduced by the aquarium trade. Lessepsian species decline westwards, while the reverse pattern is evident for ship-mediated species and for those introduced with aquaculture. There is an increasing trend in new introductions via the Suez Canal and via shipping.

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Alien species in the Mediterranean Sea by 2012. A contribution to the application of European Union’s Marine Strategy Framework Directive (MSFD). Part 2. Introduction trends and pathways

Freshwater mussels of the Order Unionida provide important ecosystem functions and services, yet many of their populations are in decline. We comprehensively review the status of the 16 currently recognized species in Europe, collating for the first time their life-history traits, distribution, conservation status, habitat preferences, and main threats in order to suggest future management actions. In northern, central, and eastern Europe, a relatively homogeneous species composition is found in most basins. In southern Europe, despite the lower species richness, spatially restricted species make these basins a high conservation priority. Information on freshwater mussels in Europe is unevenly distributed with considerable differences in data quality and quantity among countries and species. To make conservation more effective in the future, we suggest greater international cooperation using standardized protocols and methods to monitor and manage European freshwater mussel diversity. Such an approach will not only help conserve this vulnerable group but also, through the protection of these important organisms, will offer wider benefits to freshwater ecosystems.

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Conservation status of freshwater mussels in Europe: state of the art and future challenges.

Matrotrophy, the continuous extra-vitelline supply of nutrients from the parent to the progeny during gestation, is one of the masterpieces of nature, contributing to offspring fitness and often correlated with evolutionary diversification. The most elaborate form of matrotrophy—placentotrophy—is well known for its broad occurrence among vertebrates, but the comparative distribution and structural diversity of matrotrophic expression among invertebrates is wanting. In the first comprehensive analysis of matrotrophy across the animal kingdom, we report that regardless of the degree of expression, it is established or inferred in at least 21 of 34 animal phyla, significantly exceeding previous accounts and changing the old paradigm that these phenomena are infrequent among invertebrates. In 10 phyla, matrotrophy is represented by only one or a few species, whereas in 11 it is either not uncommon or widespread and even pervasive. Among invertebrate phyla, Platyhelminthes, Arthropoda and Bryozoa dominate, with 162, 83 and 53 partly or wholly matrotrophic families, respectively. In comparison, Chordata has more than 220 families that include or consist entirely of matrotrophic species. We analysed the distribution of reproductive patterns among and within invertebrate phyla using recently published molecular phylogenies: matrotrophy has seemingly evolved at least 140 times in all major superclades: Parazoa and Eumetazoa, Radiata and Bilateria, Protostomia and Deuterostomia, Lophotrochozoa and Ecdysozoa. In Cycliophora and some Digenea, it may have evolved twice in the same life cycle. The provisioning of developing young is associated with almost all known types of incubation chambers, with matrotrophic viviparity more widespread (20 phyla) than brooding (10 phyla). In nine phyla, both matrotrophic incubation types are present. Matrotrophy is expressed in five nutritive modes, of which histotrophy and placentotrophy are most prevalent. Oophagy, embryophagy and histophagy are rarer, plausibly evolving through heterochronous development of the embryonic mouthparts and digestive system. During gestation, matrotrophic modes can shift, intergrade, and be performed simultaneously. Invertebrate matrotrophic adaptations are less complex structurally than in chordates, but they are more diverse, being formed either by a parent, embryo, or both. In a broad and still preliminary sense, there are indications of trends or grades of evolutionarily increasing complexity of nutritive structures: formation of (i) local zones of enhanced nutritional transport (placental analogues), including specialized parent–offspring cell complexes and various appendages increasing the entire secreting and absorbing surfaces as well as the contact surface between embryo and parent, (ii) compartmentalization of the common incubatory space into more compact and 'isolated' chambers with presumably more effective nutritional relationships, and (iii) internal secretory ('milk') glands. Some placental analogues in onychophorans and arthropods mimic the simplest placental variants in vertebrates, comprising striking examples of convergent evolution acting at all levels—positional, structural and physiological.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/brv.12189

Matrotrophy and placentation in invertebrates: a new paradigm

Evolution of Sexual Reproduction in Marine Invertebrates: Example of gymnolaemate bryozoans

Bryozoa are unique among invertebrates in possessing placenta-like analogues and exhibiting extraembryonic nutrition in all high-level (class) taxa. Extant representatives of the classes Stenolaemata and Phylactolaemata are evidently all placental. Within the Gymnolaemata, placenta- like systems have been known since the 1910s in a few species, but are herein reported to be wide- spread within this class. Placental forms include both viviparous species, in which embryonic devel- opment occurs within the maternal body cavity, and brooding species, in which development proceeds outside the body cavity. We have also identified an unknown reproductive pattern involv- ing macrolecithal oogenesis and placental nutrition from a new, taxonomically extensive anatomical study of 120 species in 92 genera and 48 families of the gymnolaemate order Cheilostomata. Results support the hypothesis of evolution of oogenesis and placentation among Cheilostomata from oligolecithal to macrolecithal oogenesis, followed by brooding, through incipient matrotrophy com- bining macrolecithal oogenesis and placentation, to oligolecithal oogenesis with subsequent placen- tal brooding. The distribution of reproductive patterns within the phylum suggests that variations of placentation evolved in all 3 bryozoan classes, and possibly several times within both gymnolaemate orders. We infer that extraembryonic nutrition may be advantageous to species through enhanced developmental plasticity, and, in fast-growing ephemeral colonies, simultaneous volumetric growth and embryonic development may facilitate earlier larval release and occupation of vacant space.

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Independent evolution of matrotrophy in the major classes of Bryozoa: transitions among reproductive patterns and their ecological background

Rendering developmental and ecological processes into macroevolutionary events and trends has proved to be a difficult undertaking, not least because processes and outcomes occur at different scales. Here we attempt to integrate comparative analyses that bear on this problem, drawing from a system that has seldom been used in this way: the co-occurrence of alternate phenotypes within genetic individuals, and repeated evolution of distinct categories of these phenotypes. In cheilostome bryozoans, zooid polymorphs (avicularia) and some skeletal structures (several frontal shield types and brood chambers) that evolved from polymorphs have arisen convergently at different times in evolutionary history, apparently reflecting evolvability inherent in modular organization of their colonial bodies. We suggest that division of labor evident in the morphology and functional capacity of polymorphs and other structural modules likely evolved, at least in part, in response to the persistent, diffuse selective influence of predation by small motile invertebrate epibionts.

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Division of labor and recurrent evolution of polymorphisms in a group of colonial animals

Molecular techniques are currently the leading tools for reconstructing phylogenetic relationships, but our understanding of ancestral, plesiomorphic and apomorphic characters requires the study of the morphology of extant forms for testing these phylogenies and for reconstructing character evolution. This review highlights the potential of soft body morphology for inferring the evolution and phylogeny of the lophotrochozoan phylum Bryozoa. This colonial taxon comprises aquatic coelomate filter-feeders that dominate many benthic communities, both marine and freshwater. Despite having a similar bauplan, bryozoans are morphologically highly diverse and are represented by three major taxa: Phylactolaemata, Stenolaemata and Gymnolaemata. Recent molecular studies resulted in a comprehensive phylogenetic tree with the Phylactolaemata sister to the remaining two taxa, and Stenolaemata (Cyclostomata) sister to Gymnolaemata. We plotted data of soft tissue morphology onto this phylogeny in order to gain further insights into the origin of morphological novelties and character evolution in the phylum. All three larger clades have morphological apomorphies assignable to the latest molecular phylogeny. Stenolaemata (Cyclostomata) and Gymnolaemata were united as monophyletic Myolaemata because of the apomorphic myoepithelial and triradiate pharynx. One of the main evolutionary changes in bryozoans is a change from a body wall with two well-developed muscular layers and numerous retractor muscles in Phylactolaemata to a body wall with few specialized muscles and few retractors in the remaining bryozoans. Such a shift probably pre-dated a body wall calcification that evolved independently at least twice in Bryozoa and resulted in the evolution of various hydrostatic mechanisms for polypide protrusion. In Cyclostomata, body wall calcification was accompanied by a unique detachment of the peritoneum from the epidermis to form the hydrostatic membraneous sac. The digestive tract of the Myolaemata differs from the phylactolaemate condition by a distinct ciliated pylorus not present in phylactolaemates. All bryozoans have a mesodermal funiculus, which is duplicated in Gymnolaemata. A colonial system of integration (CSI) of additional, sometimes branching, funicular cords connecting neighbouring zooids via pores with pore-cell complexes evolved at least twice in Gymnolaemata. The nervous system in all bryozoans is subepithelial and concentrated at the lophophoral base and the tentacles. Tentacular nerves emerge intertentacularly in Phylactolaemata whereas they partially emanate directly from the cerebral ganglion or the circum-oral nerve ring in myolaemates. Overall, morphological evidence shows that ancestral forms were small, colonial coelomates with a muscular body wall and a U-shaped gut with ciliary tentacle crown, and were capable of asexual budding. Coloniality resulted in many novelties including the origin of zooidal polymorphism, an apomorphic landmark trait of the Myolaemata.

Andrew N. Ostrovsky

Papers

Matrotrophy and placentation in invertebrates: a new paradigm

Evolution of Sexual Reproduction in Marine Invertebrates: Example of gymnolaemate bryozoans

Independent evolution of matrotrophy in the major classes of Bryozoa: transitions among reproductive patterns and their ecological background

Division of labor and recurrent evolution of polymorphisms in a group of colonial animals

Key novelties in the evolution of the aquatic colonial phylum Bryozoa: evidence from soft body morphology.