Unified terminology for cestode microtriches: a proposal from the International Workshops on Cestode Systematics in 2002-2008

Abstract

The following terms were endorsed for the components of individual microtriches: The distal, electron-dense portion is the cap, the proximal more electron-lucent region is the base. These two elements are separated from one another by the baseplate. The base is composed of, among other elements, microfilaments. The cap is composed of cap tubules. The electron-lucent central portion of the base is referred to as the core. The core may be surrounded by an electron-dense tunic. The entire microthrix is bounded by a plasma membrane, the external layer of which is referred to as the glycocalyx. Two distinct sizes of microtriches are recognised: those ≤ 200 nm in basal width, termed filitriches, and those >200 nm in basal width, termed spinitriches. Filitriches are considered to occur in three lengths: papilliform (≤ 2 times as long as wide), acicular (2-6 times as long as wide), and capilliform (>6 times as long as wide). In instances in which filitriches appear to be doubled at their base, the modifier duplicated is used. Spinitriches are much more variable in form. At present a total of 25 spinithrix shapes are recognised. These consist of 13 in which the width greatly exceeds the thickness (i.e., bifid, bifurcate, cordate, gladiate, hamulate, lanceolate, lineate, lingulate, palmate, pectinate, spathulate, trifid, and trifurcate), and 12 in which width and thickness are approximately equal (i.e., chelate, clavate, columnar, coniform, costate, cyrillionate, hastate, rostrate, scolopate, stellate, trullate, and uncinate). Spiniform microtriches can bear marginal (serrate) and/or dorsoventral (gongylate) elaborations; they can also bear apical features (aristate). The latter two modifiers should be used only if the features are present. The terminology to describe the overall form of a spinithrix should be used in the following order: tip, margins, shape. Each type of microthrix variation is defined and illustrated with one or more scanning electron micrographs. An indication of the taxa in which each of the microthrix forms is found is also provided.

A new genus of rhinebothriidean cestodes from batoid elasmobranchs, with the description of five new species and two new combinations

“…Dried worms were mounted on carbon tabs (Ted Pella, Inc., Redding, California) on aluminium stubs, placed in a dessicator overnight, sputter coated with 250-300 Å of gold/ palladium and examined with a LEO/Zeiss DSM982 Gemini or FEI Nova Nano 450 (University of Connecticut) field emission scanning electron microscope. Microthrix terminology follows Chervy (2009)…”

Eutetrarhynchid trypanorhynchs (Cestoda) from elasmobranchs off Argentina, including the description of Dollfusiella taminii sp. n. and Parachristianella damiani sp. n., and amended description of Dollfusiella vooremi (São Clemente et Gomes, 1989)

“…After dehydration, the specimens were mounted on stubs with carbon tape, coated with c. 40 nm of gold/palladium in a Thermo VG Scientific Polaron SC 7630 and examined in a Philips XL 30 scanning electron microscope. Terminology for the morphology of microtriches follows Chervy (2009).…”

Three New Genera and Six New Species of Lecanicephalideans (Cestoda) from Eagle Rays of the Genus Aetomylaeus (Myliobatiformes: Myliobatidae) from Northern Australia and Borneo

“…Elasmobranch taxonomy follows Last and Stevens (2009) and Compagno (1999), as modified by Naylor et al (2012). Microthrix terminology follows Chervy (2009).…”