Introduction to Invertebrate Zoology PDF

INTRODUCTION TO INVERTEBRATE ZOOLOGY Outline of the Presentation What are invertebrates?  The term “invertebrate” is also paraphyletic since it excludes the Hemichordates and Urochordates, animals more closely related to vertebrates despite not having complete notochords...

INTRODUCTION TO INVERTEBRATE ZOOLOGY Outline of the Presentation What are invertebrates?  The term “invertebrate” is also paraphyletic since it excludes the Hemichordates and Urochordates, animals more closely related to vertebrates despite not having complete notochords. What makes an “invertebrate” an invertebrate? The absence of backbone shared by all “invertebrates” is not based on any biologically clear homologous trait. Homologous – derived from a common or shared ancestry A wide variety of body plans: symmetrical, asymmetrical, and radial. Absence of internal or external bones. Diversity of Invertebrates  6000 7003 12673 9795 25000 16763 64,788 85,000 Porifera 47,000 Cnidaria 102248 16072 Mollusca Annelida Arachnida Myriapoda Insecta Crustacea Platyhelminthes Nematoda Echinodermata Other invertebrates 1,000,000 Number of known species for the major invertebrate groups. (From Scheffers et al., 2012; Collen et al., 2012) Why the uncertainty? Evolutionary History Invertebrates as pioneer animals Origin of Flight Phylogeny Metazoan phylogenies. (A) The traditional phylogeny based on morphology and embryology, adapted from Hyman (11). (B) The new molecule- based phylogeny. (Adoutte et al., 2000)  Traditionally called Hypothesis of animal phylogeny “Radiata” due to radial derived from multiple symmetry phylogenomic sources. Legends: Deuterostomes – Taxa in red - unstable taxa, taxa blastopore develops with deficient into the anus genomic/transcriptomic data, or taxa for which no phylogenomic analysis is available. Taxa in blue - conflict between Lophophorate some studies, but with a protostomes: relatively stable position. characterized by the Green circles - clades presence of supported across most well- lophophores (ciliated sampled studies tentacles around the Blue circles - indicate clades mouth) and that are contradicted in some trochopore larva (a studies, especially due to the developmental stage) position of some rough taxa Ecdysozoan Red circle - a putative clade not protostomes: With thoroughly tested in three layered cuticle. phylogenomic analyses (Giribet, Able to perform 2015). ecdysis (molting) Distribution of Invertebrates But why study invertebrate zoology? Well….that is because… But seriously… In the field of medicine and disease prevention… In the field of agriculture Pollinators Pest Biological Control Agents As Food… As sources of derivatives Honey produced by bees Carmine produced from Cochineal (Dactylopius coccus)  Tyrian purple (Muricidae) – 12,000 snails = 1.4 g of dye Silk produced by mulberry silkworm (Bombyx mori)  Brazilian Wandering spider (Phonuetria sp.) venom (potential cure for erectile dysfunction) Ziconotide, an analgesic derived from Conus magus As important components of many biomes Foundation species  Conservation of the Worlds’ Invertebrates  24 species Proportion of threatened taxa in 750 species the Philippines (Gonzalez et al., 10 species 2018) Challenges in Invertebrate Conservation Avenues for research in the field of invertebrate zoology