Testing species delimitation with larval morphology: scanning electron microscopy analysis of protonymphon larvae of two closely related sea spiders, Pallenopsis patagonica (Hoek) and Pallenopsis yepayekae Weis

2017 ◽  
Vol 31 (4) ◽  
pp. 363 ◽  
Author(s):  
Jeremy Hübner ◽  
Philipp Wagner ◽  
Tobias Lehmann ◽  
Roland R. Melzer

We used scanning electron microscopy (SEM) to establish species-specific sets of characters for protonymphon larvae of two representatives of the ‘patagonica’ species group of Pallenopsis, P. patagonica and P. yepayekae. The larvae of both species are ‘typical’ protonymphon larvae sensu Bain (2003). Despite the close relationship of the two species, we observed numerous features that allow for differential diagnosis, e.g. general habitus, the number, arrangement and branching type of setules, the armature of the movable and immovable chelifore fingers, and the shape of the dactylus and setules of appendages II and III. SEM is particularly suitable for visualising these features. Our results further support the idea that protonymphon larvae can be identified to species level when adequate imaging techniques are used, as is also the case for larvae of other arthropods. Moreover, the status of the two studied species of Pallenopsis is fully supported by protonymphon larval morphology.

1971 ◽  
Vol 19 (2) ◽  
pp. 173 ◽  
Author(s):  
SGM Carr ◽  
L Milkovits ◽  
DJ Carr

The eucalypt leaf contains a store of untapped information of potentially great value taxonomic and evututionary studies. Tie cuticie of certain eucalypts is shown to possess a complex and species-specific ornamentation so distinctive that its features can be regarded as diagnostic. The term "phytoglyph" is coined for the constellation of microanatomical features of the surfaces of leaves, including the microanatomy of the cuticle. Phytoglyphic analysis relates to the combination of three methods, light microscopy of stained cuticles, scanning electron microscopy of leaf surfaces, and light microscopy of thin sections of the cuticular and associated structures. Its use is illustrated by the dissection of the "form species" E. dichromophloia into a number of separate and recognizable entities, some of which were previously accorded the status of species. The plant geographical and other implications of this dissection are dealt with. In particular, E. dichromophloia F. Muell. is to be regarded as a species of very restricted distribution. The microanatomical characters of the cuticle are closely controlled products of the epidermal layers. The fact that specimens which (on other grounds) can be grouped together as a species have identical cuticular microanatomy suggests that the phytoglyph is genetically strongly determined and does not consist of inadvertent, trivial surface features with a high degree of plasticity. This in turn raises the problem of the development of the cuticular microanatomy which cannot be explained on current views of the formation of the cuticle by passive diffusion of precursor substances through the epidermal walls, followed by a hardening process.


2018 ◽  
Vol 44 (4) ◽  
pp. 287-291
Author(s):  
Rafael Manfro ◽  
Gislaine Felipe Garcia ◽  
Marcelo Carlos Bortoluzzi ◽  
Vinicius Fabris ◽  
Atais Bacchi ◽  
...  

2000 ◽  
Vol 6 (S2) ◽  
pp. 872-873
Author(s):  
James R. Rosowski ◽  
Terry L. Bartels ◽  
James F. Colburn ◽  
Jannell L. Colton ◽  
Denton Belk ◽  
...  

Tadpole shrimp inhabit temporary freshwater pools and ponds where their occurrence is largely regulated by rainfall events and water temperature. When dry basins are flooded, cysts of Triops imbibe water and hatch to produce rapidly growing, carapaced larvae. While previous studies show anostracan (fairy shrimp) cyst-surface morphology often species specific, few studies illustrate shell ultrastructure of Triops and none has considered T. longicaudatus. Here we examine the shell of T. longicaudatus (Notostraca) and compare its fine structure to other species of Triops and to that of Artemiafranciscana(Anostraca), which we previously studied.Cysts, produced in culture from Utah broodstock, were purchased from Triops, Inc., 1924 Creighton Rd., Pensacola, FL 32504. Thin sections of cysts were prepared for transmission electron microscopy (TEM) as previously described (Fig. 1). Cysts were also examined with scanning electron microscopy (SEM), dry, whole or fractured (Figs. 2,3), or after imbibition and/or hatching in oxygen saturated, double-distilled water, at 25 ° C.


2018 ◽  
Vol 12 (03) ◽  
pp. 403-409 ◽  
Author(s):  
Ricardo Machado ◽  
Daniel Comparin ◽  
Eduardo Donato Eing Engelke Back ◽  
Lucas da Fonseca Roberti Garcia ◽  
Luiz Rômulo Alberton

ABSTRACT Objective: The purpose of this study was to compare the amount of residual smear layer after root canal instrumentation by using Ni-Ti, M-Wire, and CM-Wire instruments. Materials and Methods: Seventy-two mandibular incisors were randomly divided into six groups according to the system used: WaveOne (WO), Reciproc (RP), Unicone (UC), ProTaper Next (PN), Mtwo (MT), and HyFlex (HF). Afterward, the specimens were cleaved in the mesiodistal and buccolingual direction for analysis by scanning electron microscopy. Results: Considering both directions and root canal thirds, there was no difference between HF, MT, and PN. RP, UC, and WO presented a significant difference between the directions, and the cervical third showed a significantly smaller quantity of residual smear layer compared with the apical third. When the systems were compared among them, there was a significant difference only between RP and WO. Conclusions: Residual smear layer observed after instrumentation with the different systems was similar, except for quantities between the reciprocating systems.


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