DOCSLIB.ORG

Ianiropsis Derjugini Class: Multicrustacea, Malacostraca, Eumalacostraca

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ianiropsis Derjugini Class: Multicrustacea, Malacostraca, Eumalacostraca Phylum: Arthropoda, Crustacea Ianiropsis derjugini Class: Multicrustacea, Malacostraca, Eumalacostraca Order: Peracarida, Isopoda, Asellota An asellid isopod Family: Janiroidea, Janiridae Taxonomy: In 1952, Menzies characterized (Fig. 1). I. kincaidi and I. derjugini as subspecies of I. Antenna 1: The first antenna is quite kincaidi based on morphology and habitat. short and has a flagellum with 8–10 articles However, due to a lack of evidence of genet- (Fig. 2) (10 articles in males, Richardson ic introgression, most researchers consider 1905). them different species (e.g. Wilson and Antenna 2: The second antenna is Wagele 1994; Brusca et al. 2007). with "squama", or scales, on third article of the base (Fig. 3) (Miller 1975) and is about 2/ Description 3 length of body. The flagellum is with many Size: Up to 4 mm in length (Menzies 1952). segments and fine setae and the peduncle Figured specimen (from Charleston, Coos has six articles (Hatch 1947). Bay) was 3 mm long. Mouthparts: Maxilliped palps with arti- Color: White with brown chromatophores. cles two and three much wider than endite General Morphology: Isopod bodies are (not figured) (Miller 1975). dorso-ventrally flattened and can be divided Rostrum: Absent. into a compact cephalon, with eyes, two an- Pereon: tennae and mouthparts, and a pereon Pereonites: Seven thoracic segments (thorax) with eight segments, each bearing with variably shaped epimera (Fig. 1) and no similar pereopods (hence the name “iso- lateral spines. pod”). Posterior to the pereon is the pleon, Pereopods: The interior edge of the or abdomen, with six segments, the last of propodus is smooth, not serrated, on proximal which is fused with the telson (the pleo- third of the first pereopod (Fig. 4) (Miller telson) (see Plate 231, Brusca et al. 2007). 1975). The Isopoda can be divided into two groups: Pleon: ancestral (“short-tailed”) groups (i.e. subor- Pleonites: ders) that have short telsons and derived Pleopods: (“long-tailed”) groups with long telsons, I. Uropods: Biramous with inner branch a little derjugini groups among the former (see longer than the outer branch. The total Plate 233C, Brusca et al. 2007). The subor- uropod length is less than ½ the pleotelson der, Asellota is considered one of the ances- (Miller 1975) (Fig. 5). tral isopod groups (see Fig. 7, Brandt and Pleotelson: Shield-like with spineless lateral Poore 2003) and members are some of the borders spineless (Fig. 1) and at postero- most diverse isopods and are most success- lateral angles at insertion of uropods (Fig. 1) ful in deep sea habitats (Brusca et al. 2007; (Miller 1975) (no other Ianiropsis has this e.g. Jaera, Linse et al. 2014). character). Three posterior segments not Cephalon: Without rostrum or anteriorly pro- differentiated (Hatch 1947). jecting anterolateral angles (Fig. 1) Sexual Dimorphism: Males have a second (compare to I. k. kincaidi, Miller 1975). pleopod with modified copulatory morphology Eyes: Well-developed and reniform A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: https://oimb.uoregon.edu/oregon-estuarine-invertebrates and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] Hiebert, T.C. 2015. Ianiropsis derjugini. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR. (enlarged protopod and knee-like endopod) ent: I. kincaidi lives in small pools created (Brusca et al. 2007). by wave splash and is subject to wide tem- perature variation (Menzies 1952). On the Possible Misidentifications other hand, I. derjugini is more common un- The order Isopoda contains 10,000 der rocks that are covered by algae (Brusca species, 1/2 of which are marine and com- et al. 2007). prise 10 suborders, with eight present from Ianiropsis analoga, I. epilittoralis and central California to Oregon (see Brusca et I. tridens have spine-like serrations on the al. 2007). Among isopods with elongated sides of the pleotelson (Miller 1975). telsons (with anuses and uropods that are Ianiropsis analoga occurs from Marin subterminal), there are several groups (i.e. County, California northward, I. epilittoralis suborders) including Flabellifera, Anthu- can be found from Marin County south to ridea, Gnathiidea, Epicaridea and Valvif- San Luis Obispo, California in the high era. intertidal and I. tridens has a large range The suborder Asellota is character- from San Juan Island, Washington to ized by uropods that are styliform (Brandt Monterey County, California as well as and Poore 2003) and terminal, pleonites 3, northern Chile. Ianiropsis minuta and I. 4 or 5 fused with the pleotelson, and 1–3 montereyensis lack these serrations, forming an operculum over those posterior however I. minuta can be recognized by and pereonites without coxal plates. Thirty evenly rounded head margins and the lack -eight species comprising nine families are of the postero-lateral angles of the telson reported from central California to Oregon, and I. montereyensis has uropods that are but only 18 species are intertidal (Brusca longer than the telson. The former species et al. 2007). is reported from Marin County, California The family Janiridae (174 species, while the latter occurs from Marin to 23 genera worldwide, Linse et al. 2014) is Monterey Counties in the intertidal and a non-monophyletic isopod family (Wilson shallow subtidal zones (Brusca et al. 2007). 1994) that have 2–3 claws on the dactyls of pereopods 2–7, antennae with long fla- Ecological Information gella, and well developed uropods. There Range: Type region is the Bering Sea. are 13 species locally and seven are in the Known range from Komandorskie Islands, genus Ianiropsis, all of which are found in Bering Sea to Monterey County, California the intertidal or shallow subtidal (Brusca et (Miller 1968). al. 2007). The remaining genera include Local Distribution: Coos Bay distribution at Caecianiropsis, Caecijaera, Iais (each with the Charleston small boat basin. one local species) and Janiralata (three Habitat: Under rocks of middle and lower in- local species). tertidal zones (Menzies 1952), on buoys from Both Ianiropsis kincaidi and I. der- the surface to 1.8 m (Miller 1968). The fig- jugini were formerly subspecies of I. kin- ured specimen was collected from a within a caidi and thus, are most morphologically decayed float with the shipworm, Bankia similar. Ianiropsis kincaidi has longer uro- setacea. pods, almost half to as long as pleotelson. Salinity: Collected at a salinity of 30. Its first antennae are elongate and it lacks Temperature: Apparently not adaptable to the postero-lateral angles of I. derjugini. extreme temperatures (compre to I. k. kin- Habitats of the two subspecies are differ- caidi, Miller 1968). A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: https://oimb.uoregon.edu/oregon-estuarine-invertebrates and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] Tidal Level: Middle and lower intertidal ment and larval morphology can vary between zones (Menzies 1952) ranging from surface groups (e.g. Gnathiidae, Cryptoniscoidea, Bo- to 1.8 m deep (Miller 1968). The figured pyroidae, Cymothoidae, Oniscoidea) (see specimen was collected near the water line. Boyko and Wolff 2014). Parasitic isopods, for Associates: The shipworm, Bankia setacea example, have larvae that are morphologically and harpactacoid copepods. dissimilar from adults (Sadro 2001). Isopod Abundance: Fairly common in wood debris larvae are not common members of the plank- with Bankia setacea. ton, with parasitic larvae most likely to be ob- served. Occasionally, suspended benthic ju- Life-History Information veniles or pelagic species are collected in Reproduction: Most isopods have separate plankton samples, but these can be differenti- sexes (i.e. dioecious, Brusca and Iverson ated from larvae by their larger size (Sadro 1985) (although protogynous and protandric 2001). species are known, Araujo et al. 2004; Boy- Juvenile: ko and Wolff 2014). Reproduction proceeds Longevity: by copulation and internal fertilization where Growth Rate: Growth among isopods occurs eggs are deposited within a few hours after in conjunction with molting where the exoskel- copulation and brooded within the female eton is shed and replaced. Post-molt individ- marsupium (Brusca and Iverson 1985). The uals will have soft shells as the cuticle gradu- biphasic molting of isopods allows for copu- ally hardens. During a molt, arthropods have lation; the posterior portion of the body molts the ability to regenerate limbs that were and individuals mate, then the anterior por- previously autonomized (Kuris et al. 2007), tion, which holds the brood pouch, molts however, isopods do not autotomize limbs as (Sadro 2001). Embryonic development pro- readily as other groups (Brusca and Iverson ceeds within the brood chamber and is direct 1985). Compared to other arthropods, with individuals hatching as manca larvae isopods exhibit a unique biphasic molting, in that resemble small adults, with no larval which the posterior 1/2 of the body molts stage (Boyko and Wolff 2014). Ovigerous I. before the anterior 1/2 (Brusca et al. 2007). derjugini were collected in February, May Food: and June (northern California, Menzies Predators: Isopods play a significant role as 1952). intermediate food web links, like amphipods, Larva: Since most isopods are direct devel- (e.g. see Americorophium salmonis, this oping, they lack a definite larval stage. In- guide) that are consumed by more than 20 stead this young developmental stage re- species of marine fish (Welton and Miller sembles small adults (e.g. Fig. 40.1, Boyko 1980; cabezon, Best and Stachowicz 2012) and Wolff 2014). Most isopods develop from and whales (Brusca et al. 2007). embryo to a manca larva, consisting of three Behavior: stages. Manca larvae are recognizable by lacking the seventh pair of pereopods, but Bibliography otherwise resemble small adults.
Load more

Recommended publications
  • (Janiridae, Isopoda, Crustacea), a Second Species of Austrofilius in the Mediterranean Sea, with a Discussion on the Evolutionary Biogeography of the Genus J
    Austrofilius MAJORICENSIS SP. NOV. (JANIRIDAE, ISOPODA, CRUSTACEA), A SECOND SPECIES OF AUSTROFILIUS IN THE MEDITERRANEAN SEA, WITH A DISCUSSION ON THE EVOLUTIONARY BIOGEOGRAPHY OF THE GENUS J. Castelló To cite this version: J. Castelló. Austrofilius MAJORICENSIS SP. NOV. (JANIRIDAE, ISOPODA, CRUSTACEA), A SECOND SPECIES OF AUSTROFILIUS IN THE MEDITERRANEAN SEA, WITH A DISCUS- SION ON THE EVOLUTIONARY BIOGEOGRAPHY OF THE GENUS. Vie et Milieu / Life & Environment, Observatoire Océanologique - Laboratoire Arago, 2008, pp.193-201. hal-03246157 HAL Id: hal-03246157 https://hal.sorbonne-universite.fr/hal-03246157 Submitted on 2 Jun 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. VIE ET MILIEU - LIFE AND ENVIRONMENT, 2008, 58 (3/4): 193-201 AUSTROFILIUS MAJORICENSIS SP. NOV. (JANIRIDAE, ISOPODA, CRUSTACEA), A SECOND SPECIES OF AUSTROFILIUS IN THE MEDITERRANEAN SEA, WITH A DISCUSSION ON THE EVOLUTIONARY BIOGEOGRAPHY OF THE GENUS J. CASTELLÓ Departament de Didàctica de les Ciències Experimentals i de la Matemàtica, Universitat de Barcelona, Passeig de la Vall d’Hebron 171, 08035 Barcelona, Spain [email protected] ISOPODA Abstract. – A new species of Janiroidean isopod, Austrofilius majoricensis sp. nov., from ASELLOTA JANIRIDAE Majorca (Balearic Islands, Western Mediterranean), is described.
    [Show full text]
  • OREGON ESTUARINE INVERTEBRATES an Illustrated Guide to the Common and Important Invertebrate Animals
    OREGON ESTUARINE INVERTEBRATES An Illustrated Guide to the Common and Important Invertebrate Animals By Paul Rudy, Jr. Lynn Hay Rudy Oregon Institute of Marine Biology University of Oregon Charleston, Oregon 97420 Contract No. 79-111 Project Officer Jay F. Watson U.S. Fish and Wildlife Service 500 N.E. Multnomah Street Portland, Oregon 97232 Performed for National Coastal Ecosystems Team Office of Biological Services Fish and Wildlife Service U.S. Department of Interior Washington, D.C. 20240 Table of Contents Introduction CNIDARIA Hydrozoa Aequorea aequorea ................................................................ 6 Obelia longissima .................................................................. 8 Polyorchis penicillatus 10 Tubularia crocea ................................................................. 12 Anthozoa Anthopleura artemisia ................................. 14 Anthopleura elegantissima .................................................. 16 Haliplanella luciae .................................................................. 18 Nematostella vectensis ......................................................... 20 Metridium senile .................................................................... 22 NEMERTEA Amphiporus imparispinosus ................................................ 24 Carinoma mutabilis ................................................................ 26 Cerebratulus californiensis .................................................. 28 Lineus ruber .........................................................................
    [Show full text]
  • Systematics, Zoogeography, Evolution and Biodiversity of Antarctic Deep-Sea Isopoda (Crustacea: Malacostraca)
    Systematics, zoogeography, evolution and biodiversity of Antarctic deep-sea Isopoda (Crustacea: Malacostraca) Dissertation zur Erlangung des Doktorgrades des Fachbereichs Biologie der Universität Hamburg vorgelegt von Wiebke Brökeland aus Essen Hamburg 2005 Our knowledge can only be finite, while our ignorance must necessarily be infinite. Karl Raimund Popper According to ICZN article 8.3 all names and nomenclatural acts in this thesis are disclaimed for nomenclatural purposes. Table of contents Summary..................................................................................................................................... i 1 Introduction............................................................................................................................ 1 1.1 The deep sea................................................................................................................................. 1 1.2 The Southern Ocean ................................................................................................................... 2 1.3 Deep-sea Isopoda......................................................................................................................... 3 1.4 Aims and questions ..................................................................................................................... 5 2 Material and Methods ............................................................................................................ 6 2.1 Sampling .....................................................................................................................................
    [Show full text]
  • Connecticut Aquatic Nuisance Species Management Plan
    CONNECTICUT AQUATIC NUISANCE SPECIES MANAGEMENT PLAN Connecticut Aquatic Nuisance Species Working Group TABLE OF CONTENTS Table of Contents 3 Acknowledgements 5 Executive Summary 6 1. INTRODUCTION 10 1.1. Scope of the ANS Problem in Connecticut 10 1.2. Relationship with other ANS Plans 10 1.3. The Development of the CT ANS Plan (Process and Participants) 11 1.3.1. The CT ANS Sub-Committees 11 1.3.2. Scientific Review Process 12 1.3.3. Public Review Process 12 1.3.4. Agency Review Process 12 2. PROBLEM DEFINITION AND RANKING 13 2.1. History and Biogeography of ANS in CT 13 2.2. Current and Potential Impacts of ANS in CT 15 2.2.1. Economic Impacts 16 2.2.2. Biodiversity and Ecosystem Impacts 19 2.3. Priority Aquatic Nuisance Species 19 2.3.1. Established ANS Priority Species or Species Groups 21 2.3.2. Potentially Threatening ANS Priority Species or Species Groups 23 2.4. Priority Vectors 23 2.5. Priorities for Action 23 3. EXISTING AUTHORITIES AND PROGRAMS 30 3.1. International Authorities and Programs 30 3.2. Federal Authorities and Programs 31 3.3. Regional Authorities and Programs 37 3.4. State Authorities and Programs 39 3.5. Local Authorities and Programs 45 4. GOALS 47 3 5. OBJECTIVES, STRATEGIES, AND ACTIONS 48 6. IMPLEMENTATION TABLE 72 7. PROGRAM MONITORING AND EVALUATION 80 Glossary* 81 Appendix A. Listings of Known Non-Native ANS and Potential ANS in Connecticut 83 Appendix B. Descriptions of Species Identified as ANS or Potential ANS 93 Appendix C.
    [Show full text]
  • Isopoda, Asellota, Janiridae) from Korean Waters
    Anim. Syst. Evol. Divers. Vol. 37, No. 2: 146-153, April 2021 https://doi.org/10.5635/ASED.2021.37.2.006 Short communication Description of Janiralata sagamiensis (Isopoda, Asellota, Janiridae) from Korean Waters Sung Hoon Kim1, Seong Myeong Yoon2,3,* 1Division of Ocean Sciences, Korea Polar Research Institute, Incheon 21990, Korea 2Department of Biology, College of Natural Sciences, Chosun University, Gwangju 61452, Korea 3Educational Research Group for Age-associated Disorder Control Technology, Graduate School, Chosun University, Gwangju 61452, Korea ABSTRACT Janirid isopod, Janiralata sagamiensis Shimomura, 2006 is newly reported from Korean waters. This species can be distinguishable from its congeners by the following characteristics: the cephalon has a distinct anterolateral projection on the anterolateral margin; the frontal margin of the cephalon is lacking rostrum; the coxal plates are visible in dorsal view; the pleotelson is rounded distally without a posterolateral point; the first pleopod of the male has a pair of protrusions distally; the third pleopodal exopod is lacking plumose setae. In this paper, the detailed description and illustrations of the species are provided with a key to known Janiralata species in the surrounding waters of Korea, including China and Japan. Keywords: Janiralata, Janiridae, isopods, morphology, Korea INTRODUCTION ralata species have been known, including single record from Korea: J. chuni (Thielemann, 1910) from Japan; J. koreaensis The Janiralata Menzies, 1951, comprising 32 species, is the Jang, 1991 from Korea; J. sagamiensis Shimomura, 2006 third largest genus after the Jaera Leach, 1814 and Janira from Japan; J. shiinoi Kussakin, 1962 from the East China Leach, 1814 among 30 genera of the family Janiridae G.
    [Show full text]
  • The Shallow-Water Asellota (Crustacea: Isopoda) from the Beagle Channel: Preliminary Taxonomic and Zoogeographical Results*
    SCI. MAR., 69 (Suppl. 2): 159-166 SCIENTIA MARINA 2005 THE MAGELLAN-ANTARCTIC CONNECTION: LINKS AND FRONTIERS AT HIGH SOUTHERN LATITUDES. W.E. ARNTZ, G.A. LOVRICH and S. THATJE (eels.) The shallow-water Asellota (Crustacea: Isopoda) from the Beagle Channel: Preliminary taxonomic and zoogeographical results* BRENDA LIA DOTI>, DANIEL ROCCATAGLIATA ' and DIEGO GABRIEL ZELAYA2 1 Departamento de Biodiversidad y Biologi'a Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina. E-mail: [email protected] 2Museo de La Plata, Paseo del Bosque s/n, (1900) La Plata, Provincia de Buenos Aires, Argentina. SUMMARY: The shallow-water Asellota from the Beagle Channel were investigated, based on material collected at four localities in 2001-2002. A total of 3,124 asellotes were sorted, and three new species and 12 new records of distribution were reported. The Paramunnidae showed the highest species diversity and abundance (11 species and 1,463 specimens). The pre­ sent research raises the number of species known from the Beagle Channel to 23; of these, 16 were previously reported from the Magellan Straits, representing 69% of similarity. Based on the present results and published data, the faunistic affinities for the shallow-water Asellota was 30% between the Magellan region and the Scotia Arc, and 26% between the Magellan region and the Antarctic Peninsula. Keywords: Asellota, Isopoda, diversity, Beagle Channel, Magellan region. RESUMEN: ASELLOTA (CRUSTACEA: ISOPODA) DE AGUAS SOMERAS DEL CANAL BEAGLE: PRIMEROS RESULTADOS TAXONOMI- cos Y BIOGEOGRAFICOS. - Se estudiaron los isopodos Asellota colectados en cuatro localidades de aguas poco profundas del Canal Beagle en el 2001 y 2002.
    [Show full text]
  • Effects of Dysbiosis and Dietary Manipulation on the Digestive Microbiota of a Detritivorous Arthropod
    microorganisms Article Effects of Dysbiosis and Dietary Manipulation on the Digestive Microbiota of a Detritivorous Arthropod Marius Bredon 1 , Elisabeth Depuydt 1, Lucas Brisson 1, Laurent Moulin 2, Ciriac Charles 2,3, Sophie Haenn 2, Bouziane Moumen 1 and Didier Bouchon 1,* 1 UMR CNRS 7267, Ecologie et Biologie des Interactions, Université de Poitiers, F-86073 Poitiers, France; [email protected] (M.B.); [email protected] (E.D.); [email protected] (L.B.); [email protected] (B.M.) 2 Eau de Paris, Direction de la Recherche et du Développement pour la Qualité de l’Eau, R&D Biologie, F-94200 Ivry sur Seine, France; [email protected] (L.M.); [email protected] (C.C.); [email protected] (S.H.) 3 Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail, F-94700 Maisons-Alfort, France * Correspondence: [email protected]; Tel.: +33-(0)5-49-45-38-95; Fax: +33-(0)5-49-45-40-15 Abstract: The crucial role of microbes in the evolution, development, health, and ecological interac- tions of multicellular organisms is now widely recognized in the holobiont concept. However, the structure and stability of microbiota are highly dependent on abiotic and biotic factors, especially in the gut, which can be colonized by transient bacteria depending on the host’s diet. We studied these impacts by manipulating the digestive microbiota of the detritivore Armadillidium vulgare and analyzing the consequences on its structure and function. Hosts were exposed to initial starvation and then were fed diets that varied the different components of lignocellulose.
    [Show full text]
  • Native and Exotic Amphipoda and Other Peracarida in the River Meuse: New Assemblages Emerge from a Fast Changing Fauna
    Hydrobiologia (2005) 542:203–220 Ó Springer 2005 H. Segers & K. Martens (eds), Aquatic Biodiversity II DOI 10.1007/s10750-004-8930-9 Native and exotic Amphipoda and other Peracarida in the River Meuse: new assemblages emerge from a fast changing fauna Guy Josens1,*, Abraham Bij de Vaate2, Philippe Usseglio-Polatera3, Roger Cammaerts1,4, Fre´de´ric Che´rot1,4, Fre´de´ric Grisez1,4, Pierre Verboonen1 & Jean-Pierre Vanden Bossche1,4 1Universite´ Libre de Bruxelles, Service de syste´matique et d’e´cologie animales, av. Roosevelt, 50, cp 160/13, B-1050 Bruxelles 2Institute for Inland Water Management & Waste Water Treatment, Lelystad, The Netherlands 3Universite´ de Metz, LBFE, e´quipe de De´moe´cologie, av. Ge´ne´ral Delestraint, F-57070 Metz 4Centre de Recherche de la Nature, des Foreˆts et du Bois, DGRNE, Ministe`re de la Re´gion wallonne, Avenue Mare´chal Juin, 23, B-5030 Gembloux (*Author for correspondence: e-mail: [email protected]) Key words: aquatic biodiversity, alien species, invasive species, invasibility, community dynamics, Dikerogammarus villosus, Chelicorophium curvispinum Abstract Samples issued from intensive sampling in the Netherlands (1992–2001) and from extensive sampling carried out in the context of international campaigns (1998, 2000 and 2001) were revisited. Additional samples from artificial substrates (1992–2003) and other techniques (various periods) were analysed. The combined data provide a global and dynamic view on the Peracarida community of the River Meuse, with the focus on the Amphipoda. Among the recent exotic species found, Crangonyx pseudogracilis is regressing, Dikerogammarus haemobaphes is restricted to the Condroz course of the river, Gammarus tigrinus is restricted to the lowlands and seems to regress, Jaera istri is restricted to the ‘tidal’ Meuse, Chelicorophium curvispinum is still migrating upstream into the Lorraine course without any strong impact on the other amphipod species.
    [Show full text]
  • The Fine Structure of the Compound Eyes of Shallow-Water Asellotes, Jaera Albifrons Leach and Asellus Aquaticus L
    Acta*.uui. (oiocKti.j M: 69—84 (1978) The Fine Structure of the Compound Eyes of Shallow-Water Asellotes, Jaera albifrons Leach and Asellus aquaticus L. (Crustacea: Isopoda) Heimo L. Nilsson Department of Zoology, University of Lund, Sweden (Accepted February 24, 1978) Abstract Nilsson, H. L. 1978. The fine structure of the compound eyes of shallow-water asellotes, Jaera albifrons Leach and Asellus aquaticus L. (Crustacea: Isopoda). (Department of Zoology, University of Lund, Sweden.) — Acta zool. (Stockh.) 59(2): 69—84. Both species have small sessile compound eyes. The dioptric apparatus of /. albifrons consists of a biconvex lens and a pyriform crystalline cone, the latter formed by two principal and two accessory cone cells. A. aquaticus has a reduced lens and a round cone formed by two to four principal cone cells with two to no accessory cone cells. Distal pigment cells and pigmented retinular cells lie between the ommatidia in /. albifrons. A. aquaticus has only the pigmented retinular cells. Both species have a fused, continuous (unbanded) rhabdom formed by eight retinular cells (Rl—8), one of which (R8) is situated distally. The retinular cells Rl—7 form, in /. albifrons, a cylinder- shaped middle portion with three microvillar directions (60° apart) and a proximal star-shaped portion. The entire rhabdom of A. aquaticus is star- shaped. Distal pigment-cell processes and basal cells form the fenestrated membrane in /. albifrons and ueye-cup cells" in A. aquaticus. Heimo L. Nilsson, Department of Zoology, University of Lund, Helgonavdgen 3, S-223 62 Lund, Sweden. dillo officinalis (Bengucrrah and Carricaburu Introduction 1976). A great variation in the organization of the isopod All of these above-cited investigations indicate retinae has been shown by previous light-micro­ that the isopod compound eye and visual proper­ scopic studies (e.g.
    [Show full text]
  • The Freshwater Fauna of the South Polar Region: a 140-Year Review
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Tasmania Open Access Repository Papers and Proceedings of the Royal Society of Tasmania, Volume 151, 2017 19 THE FRESHWATER FAUNA OF THE SOUTH POLAR REGION: A 140-YEAR REVIEW. by Herbert J.G. Dartnall (with one text-figure, one table and one appendix) Dartnall, H.J.G. 2017 (6:xii): The freshwater fauna of the South Polar Region: A 140-year review. Papers and Proceedings of the Royal Society of Tasmania 151: 19–57. https://doi.org/10.26749/rstpp.151.19 ISSN 0080-4703. Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109 Australia. E-mail: [email protected] The metazoan fauna of Antarctic and sub-Antarctic freshwaters is reviewed. Almost 400 species, notably rotifers, tardigrades and crustaceans have been identified. Sponges, molluscs, amphibians, reptiles and fishes are absent though salmonid fishes have been successfully introduced on some of the sub-Antarctic islands. Other alien introductions include insects (Chironomidae) and annelid worms (Oligochaeta). The fauna is predominately benthic in habitat and becomes increasingly depauperate at higher latitudes. Endemic species are known but only a few are widely distributed. Planktonic species are rare and only one parasitic species has been noted. Keywords: freshwater, fauna, Antarctica, sub-Antarctic Islands, maritime Antarctic, continental Antarctica. INTRODUCTION included in this definition. While these cool-temperate islands have a similar verdant vegetation and numerous The first collections of Antarctic freshwater invertebrates water bodies they are warmer and some are vegetated with were made during the “Transit of Venus” expeditions woody shrubs and trees.] of 1874 (Brady 1875, 1879, Studer 1878).
    [Show full text]
  • Invertebrate Monitoring As Measure of Ecosystem Change Mélissa Jane
    Invertebrate monitoring as measure of ecosystem change Mélissa Jane Houghton B. Arts and Sciences M. Environmental Management A thesis submitted for the degree of Doctor of Philosophy at The University of Queensland in 2020 School of Biological Sciences Centre for Biodiversity and Conservation Science Abstract Islands and their biodiversity have high conservation value globally. Non-native species are largely responsible for island extinctions and island ecosystem disruption and are one of the major drivers of global biodiversity loss. Developing tools to effectively measure and understand island ecosystem change is therefore vital to future island conservation management, specifically island communities and the threatened species within them. One increasing utilised island conservation management tool is invasive mammal eradication. Such programs are increasing in number and success, with high biodiversity gains. Typically, it is assumed that the removal of target non-native species equates to management success and in some instances, recovery of a key threatened or charismatic species affected by the pest species are monitored. Yet to date, there are few published studies quantifying post- eradication ecosystem responses. Such monitoring helps to calculate return-on-investment, understand the conservation benefits of management and inform conservation decision- making associated with current and future restoration programs. Not only are there few studies providing empirical evidence of whole-of-ecosystem recovery following mammal eradications,
    [Show full text]
  • Maei14can%Mlseum
    aei14canM %Mlseum PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK 24, N.Y. NUMBER 1798 OCTOBER 16, 1956 New Abyssal Tropical Atlantic Isopods, with Observations on Their Biology' BY ROBERT J. MENZIES2 INTRODUCTION AND ACKNOWLEDGMENTS On November 12, 1955, the R/V "Vema" of the Lamont Geological Observatory completed a successful deep sea trawl over an abyssal plain on the north rim of the Puerto Rico Trench at a depth of 2700-2710 fathoms. This haul contained one ophiuroid, one bivalve mollusk, several polychaets, a few amphipods, and one of the largest collections of isopods (eight species) ever made with one trawl at such great depth. The trawl used was the Closing-Opening Epibenthic Trawl designed by Mr. Robert Bieri of this laboratory. An earlier model which was not of the opening and closing type has been figured and described (Devereux, 1954). The trawl was made at latitude 20° 32.2' N. and longitude 600 28.1' W. The surface- mud was a brownish, finely particulate ooze, below which was a foraminiferal ooze. Earlier Atlantic deep sea expeditions have reported on abyssal isopods, and it may be assumed that the fauna of the North Atlantic is fairly com- pletely known. Hansen (1916) recorded 84 species from below 1000 fathoms. In all he described 121 species between latitudes 600 and 700 in the Atlantic. Richardson (1908) has described the species collected by the "Albatross." The results of the Danish "Galathea" expedition are not yet available. 1 Lamont Geological Observatory Contribution No. 199, Biology Program Num- ber 3.
    [Show full text]