Sea Urchins

Biology and Ecology

John M. Lawrence

• Publisher: Academic Press
• Year: 2020
• ISBN:
  9780128195697
• Edition: 4
• Topic: Technology & Engineering
• Subtopic: Fisheries & Aquaculture
• Index: Technology & Engineering

Sea Urchins: Biology and Ecology, Fourth Edition, Volume 43 expands its coverage to include the entire class of Echinoidea, making this new edition an authoritative reference of the entire class of species. This is a valuable resource that will help readers gain a deep understanding of the basic characteristics of sea urchins, the basis of the great variation that exists in sea urchins, and how sea urchins are important components of marine ecosystems. Updated coverage includes sections on reproduction, metabolism, endocrinology, larval ecology, growth, digestion, carotenoids and disease.

• Includes pertinent tables and graphs within chapters to visually summarize information
• Provides case studies with research applications to provide potential solutions
• Includes the entire class of Echinoidea and the effect of climate change on the biology and ecology of the species

Chapter 1

Phylogeny and classification of echinoids

Andreas Kroh* Department of Geology and Palaeontology, Natural History Museum Vienna, Vienna, Austria
* Corresponding author: email address: [email protected]

Abstract

The rich fossil record of echinoids documents their 460 million years long evolutionary history and provides a treasure trove for phylogenetic studies. The multielement high-magnesium calcite skeleton of echinoids offers a huge range of phylogenetically useful information applicable to both extant and fossil specimens. This allows seamless integration of modern and extinct taxa in joint analyses, likely being responsible for the high congruence between phylogenies based on morphological and molecular markers. The present paper reviews the current knowledge on echinoid phylogeny and proposes a revised classification incorporating novel results published since 2010.

The availability of numerous phylogenetic studies based on morphological data sets is in stark contrast to a relatively small set of phylogenetic studies involving molecular data. Genetic data, particularly phylogenomic data, are still missing for many of the major lineages. Such data are expected to help establish a robust phylogenetic backbone in areas where trees derived from morphological data show weak support and/or topologies that are affected by alteration of the taxon and character set used. The reasons for the difficulties to resolve these relationships seem to be rooted in convergent evolution, secondary loss of derived features, and a tendency for the evolution of paedomorphic forms in some lineages.

Keywords

Echinoidea; Phylogeny; Classification; Diversification; Fossil record

1 Introduction

The evolutionary history of echinoids dates back to the Darriwilian (Middle Ordovician), ca. 460 million years ago (Paul, 1967; Smith and Savill, 2001) and is well documented by their extensive fossil record. A relatively small number of extant species of echinoids (slightly over 1000; Kroh and Mooi, 2019) is opposed by a rich fossil record with many nominal fossil species (ca. 10,000; Lambert and Thiéry, 1909–1925; Kier and Lawson, 1978; Kroh, 2010). The multielement calcite skeleton of echinoids offers a huge range of phylogenetically useful information applicable to both recent and fossil specimens, thus allowing seamless integration of extant and fossil taxa in joint analyses. This may be the reason why, unlike many other groups, echinoids show high congruence between phylogenies based on morphological and molecular markers (Smith and Kroh, 2013).

Here the current knowledge on echinoid phylogeny is reviewed. It draws heavily upon the results of a phylogenetic analysis based on ribosomal gene sequence data by Smith et al. (2006) and an extensive morphological cladistic analysis by Kroh and Smith (2010), which had full coverage at the family level. For a review of the history of echinoid classification prior to 1966, see Durham (1966) and for the period from 1966 to 2010, see Smith and Kroh (2013).

The revised classification presented herein incorporates novel results from morphological as well as phylogenetic and phylogenomic studies published since 2010 and new decisions by the ICZN (International Commission on Zoological Nomenclature). In addition, it corrects some errors in the classification presented by Kroh and Smith (2010). Clearly, this classification will need to be modified as taxon sampling, particularly of phylogenomic analyses, increases and areas of conflict between morphological and molecular data are resolved. This revised classification is a first draft of a “working classification” for the ongoing effort on a revised version of the Echinoidea part of the Treatise on Invertebrate Paleontology. It is put forward for discussion by the scientific community, in order to highlight areas in the echinoid tree of life in need of increased research effort.

2 Class Echinoidea Leske, 1778

2.1 Stem group Echinoidea (Paleozoic echinoids)

Paleozoic echinoids are a grade taxon (i.e., a paraphyletic group) united by their shared plesiomorphic characters, which are a corona composed of more than two columns of ambulacral and/or interambulacral plates in each zone and the absence of a perignathic girdle. The most comprehensive treatment of Paleozoic echinoids was and is the monograph of Jackson (1912). Their morphological diversification was described by Kier (1965). The only phylogenetic analysis published is that of Smith (1984: p. 145 ff), who proposed a classification based on the plesion concept of Patterson and Rosen (1977). Bothriocidaroids were excluded from his analysis since Smith (1984: fig. 9.4) considered them a sister taxon to ophiocistioids and thus stem holothurioids rather than echinoids. With the discovery of Bromidechinus, this view changed and bothriocidaroids are currently considered a sister group to the main echinoid line that postdate the split with ophiocistioids (Smith and Savill, 2001). The working classification for Paleozoic echinoids presented below is a hybrid between the results of Smith (1984) and data presented in the Echinoid Directory (Smith and Kroh, 2011). A novel phylogenetic anal...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Chapter 1: Phylogeny and classification of echinoids
• Chapter 2: Sea urchin life-history strategies
• Chapter 3: Gametogenesis in regular sea urchins: Structural, functional, and molecular/genomic biology
• Chapter 4: Biochemical and energy requirements of gonad development in regular sea urchins
• Chapter 5: Endocrine regulation of regular echinoid reproduction
• Chapter 6: Larval ecology of echinoids
• Chapter 7: Growth and survival of postsettlement sea urchins
• Chapter 8: Digestive system in regular sea urchins
• Chapter 9: Ingestion, digestion, and digestibility of regular sea urchins
• Chapter 10: Nutrition
• Chapter 11: Carotenoids in sea urchins
• Chapter 12: Sea urchin diseases: Effects from individuals to ecosystems
• Chapter 13: Immunology in sea urchins
• Chapter 14: Deep-sea sea urchins
• Chapter 15: Regular sea urchins as drivers of shallow benthic marine community structure
• Chapter 16: Sea urchins in a high CO2 world: Impacts of climate warming and ocean acidification across life history stages
• Chapter 17: Stock enhancement of regular sea urchins
• Chapter 18: Ecology of clypeasteroids
• Chapter 19: Peronella
• Chapter 20: Echinocardium cordatum
• Chapter 21: Cidaroids
• Chapter 22: Centrostephanus rodgersii and Centrostephanus tenuispinus
• Chapter 23: Diadema
• Chapter 24: Arbacia
• Chapter 25: Loxechinus albus
• Chapter 26: Paracentrotus lividus
• Chapter 27: Psammechinus miliaris
• Chapter 28: Echinometra
• Chapter 29: Evechinus chloroticus
• Chapter 30: Heliocidaris erythrogramma
• Chapter 31: Strongylocentrotus droebachiensis
• Chapter 32: Mesocentrotus franciscanus and Strongylocentrotus purpuratus
• Chapter 33: Strongylocentrotus intermedius
• Chapter 34: Mesocentrotus nudus
• Chapter 35: Hemicentrotus pulcherrimus, Pseudocentrotus depressus, and Heliocidaris crassispina
• Chapter 36: Lytechinus
• Chapter 37: Tripneustes
• Index