scholarly journals Projected shifts in deadwood bryophyte communities under national climate and forestry scenarios benefit large competitors and impair small species

2021 ◽  
Author(s):  
Swantje Löbel ◽  
Boris Schröder ◽  
Tord Snäll
Keyword(s):  
Small Species

Torpor and hibernation

2017 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Body Temperature ◽  
Small Mammals ◽  
Energy Input ◽  
The Arctic ◽  
Arid Areas ◽  
Daily Torpor ◽  
High Latitudes ◽  
Small Species ◽  
Universal Feature ◽  
Deep Hibernation

A diurnal (circadian) rhythm in body temperature is a widespread, and possibly universal, feature of endotherms. Some mammals and birds down-regulate their metabolic rate significantly by night, allowing their body temperature to drop sufficiently that they become inactive and enter torpor. Both the minimum temperature achieved and the duration of torpor are highly variable. Daily torpor is principally a response to reduced energy intake, and a drop in ambient temperature. Hibernation is essentially an extreme form of torpor. Small mammals hibernating at high latitudes have regular arousals during which they urinate and may feed. Bears hibernate with relatively high body temperature, and do not undergo arousal. Only one bird, the poorwill, is known to hibernate. Rewarming during arousal may be fuelled exclusively by metabolism (for example in small mammals in the Arctic) or with significant energy input from basking (for example in subtropical arid areas). The capacity for torpor appears to be an ancestral character in both mammals and birds, possibly related to the origin of endothermy in small species subject to marked diurnal and/or seasonal variation in body temperature. Both deep hibernation and strict endothermy are probably derived characteristics.

Sellaphora labernardierei (Sellaphoraceae, Bacillariophyta), a new epilithic species from French spring and four new combinations within the genus Sellaphora

Phytotaxa ◽  
2016 ◽  
Vol 260 (3) ◽  
pp. 235 ◽  
Author(s):  
AUDE BEAUGER ◽  
CARLOS E. WETZEL ◽  
OLIVIER VOLDOIRE ◽  
ALEXANDRE GARREAU ◽  
LUC ECTOR
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Central Area ◽  
Mineral Waters ◽  
New Combinations ◽  
French Massif Central ◽  
Small Species ◽  
Massif Central ◽  
Floristic Survey ◽  
Scanning Electron

During a floristic survey of freshwater springs in the French Massif Central region, a new Sellaphora species (Bacillariophyceae) was found and is hereby described: Sellaphora labernardierei sp. nov. This new small species, with linear to linear-elliptical valves, slightly inflated in the middle, is formally described using light and scanning electron microscopy. The species has a single H-shaped chloroplast and striae usually biseriate tending to be uniseriate near the centre of the valve. The valve dimensions, the valve, pole and central area shapes, and the striae density and pattern allow their separation from similar taxa belonging to the genera Eolimna, Naviculadicta and Sellaphora. The ecological preferences of Sellaphora labernardierei are mineral waters with high nitrate concentrations. The examination of similar taxa belonging to the genera Eolimna and Naviculadicta and their characteristics lead to propose four new combinations of Sellaphora species.

ChemInform Abstract: Molecular Similarity for Small Species: Refining the Isoelectronic Index.

ChemInform ◽  
2010 ◽  
Vol 32 (34) ◽  
pp. no-no
Author(s):  
Ray Hefferlin ◽  
Myla Thomas Matus
Keyword(s):  
Molecular Similarity ◽  
Small Species

scholarly journals Description of two new sympatric species of the genus Hisonotus Eigenmann and Eigenmann, 1889, from upper Rio Tapajós, Mato Grosso state, Brazil (Pisces: Ostariophysi: Loricariidae)

2007 ◽  
Vol 67 (3) ◽  
pp. 413-420 ◽  
Author(s):  
HA. Britski ◽  
JC. Garavello
Keyword(s):  
New Species ◽  
Anterior Part ◽  
Sympatric Species ◽  
Growing Up ◽  
Small Species ◽  
Mato Grosso ◽  
Moderate Number ◽  
Two New Species ◽  
Yellow Line

Two new species of the genus Hisonotus are described from the upper Rio Tapajós basin, Mato Grosso State, Brazil. They are small species, growing up to about 30.0 mm SL, having the scapular bridge wide and totally exposed or having a small median pair of arrector fossae, and the abdomen completely covered with large plates in adult specimens (about 23.0 mm SL). They are distinguished from their congeners by the following combination of characters: Hisonotus chromodontus has 20-40 reddish-brown tipped premaxillary teeth, and 15-38 on the dentary bones; 2324 plates on the longitudinal series; a prominent large dark brown lateral stripe extending from the tip of the snout to the caudal blotch; transversal dark brown bars very inconspicuous or absent. Hisonotus luteofrenatus has a moderate number (12-28) of hyaline or slightly yellow-tipped premaxillary teeth, and 9-26 on the dentary bones; 25-26 plates on the longitudinal series; a characteristic yellow line extending from the anterior part of each orbit, over the inferior nostril, both converging to the tip of the snout.

scholarly journals The Eyes and the Photonegative Behaviour of Nephtys (Annelida, Polychaeta)

1956 ◽  
Vol 33 (3) ◽  
pp. 461-477
Author(s):  
R. B. CLARK
Keyword(s):  
Light Intensity ◽  
Light Beam ◽  
Linear Function ◽  
Posterior Part ◽  
Dorsal Surface ◽  
Epidermal Cells ◽  
Small Species ◽  
Accessory Cells ◽  
Vacuolated Cells ◽  
The Brain

1. The photoreceptors found in the Nephtyidae are: (a) Two pairs of vacuolated cells lying in pigment cups, with accessory cells, embedded in the posterior part of the supra-oesophageal ganglion. (b) One or two cells, which may or may not be vacuolated, on either side, lying a little anterior to the ganglion. (c) Undifferentiated epidermal cells surrounded by pigment granules may be photosensitive. 2. There are both morphological and behavioural grounds for concluding that the prostomial eyes of Nephtys are homologous with the eyes of Nereis, and that they are involved in the same types of behaviour. 3. The frequency with which Nephtys swims is, within limits, a linear function of the light intensity. Although the ganglionic eyes are directional receptors the worm does not orientate itself in a light beam; presumably the light reaching them is too diffuse. In the very small species N. cornuta, the eyes are close to the surface of the brain and the worm does orientate itself in a light beam. 4. Swimming is an essential prelude to burrowing, and the brighter the light the more frequently the worm swims and the sooner it is buried. Activity in light can be inhibited by stimulating receptors on the dorsal surface of the animal by contact.

Zooplankton in a Danube River Arm near Rusovce (Slovakia)

Biologia ◽  
2008 ◽  
Vol 63 (4) ◽  
Author(s):  
Marta Illyová ◽  
Katarína Bukvayová ◽  
Danka Némethová
Keyword(s):  
Water Temperature ◽  
Zooplankton Biomass ◽  
Danube River ◽  
Total Abundance ◽  
Small Species ◽  
Annual Average ◽  
Keratella Cochlearis ◽  
Chydorus Sphaericus ◽  
Cyclops Vicinus ◽  
The Right

AbstractPoor quantity of zooplankton was recorded in a Danube arm situated on the right side of the Danube River in Slovakia (river km 1857) in 2002 and 2003. All over the year the arm is significantly influenced by groundwater by reason of seepage. Because of low mean water temperature (12°C) and poorly developed macrovegetation in particular, the arm reminds gravel pit-like. The annual average of zooplankton biomass was low and ranged from 0.35 g m−3 (2002) to 1.28 g m−3 (2003), because of low crustacean abundance. Total cladoceran abundance was excessively low in both years and ranged from 3.5 N L−1 (2002) to 16.6 N L−1 (2003). Small species, Bosmina longirostris and Chydorus sphaericus were dominant. Only four adult Copepoda — Cyclops vicinus, Thermocyclops crassus, Eurytemora velox and Eudiaptomus gracilis — were recorded in quantitative samples of both years. In the zooplankton assemblage dominated rotifers (Synchaeta pectinata, Synchaeta oblonga, Polyarthra dolichoptera and Keratella cochlearis) which represented 78% and 67% of total abundance respectively. The total of 19 species of rotifers, 34 Cladocera species and 16 taxa of Copepoda were found.

Shelter selection by a small mammal community in the wet-dry tropics of Australia.

1989 ◽  
Vol 12 (2) ◽  
pp. 55
Author(s):  
R.W. Braithwaite
Keyword(s):  
Habitat Selection ◽  
Small Mammal ◽  
Tree Species ◽  
Average Distance ◽  
Small Species ◽  
Dry Tropics ◽  
Open Forest ◽  
Shelter Selection ◽  
Small Mammal Community ◽  
The Mean

The location of shelter used by nine species of small mammals released after capture during a mark-recapture study in tropical woodland and open forest was recorded whenever possible. A quantitative profile of such post-release behaviour by different species permits its incorporation into analyses of habitat selection. Characteristics of post-release behaviour also provide clues about the nature of predation pressure on various species. Arboreal species tended to select tree species with boles having camouflage potential. Small species used small holes. Scansorial species used the greatest range of sheltering sites. Average distance moved to shelter was inversely related to the mean density of a species.

Four new species of monoraphid diatoms from Western Sichuan Plateau in China

Phytotaxa ◽  
2021 ◽  
Vol 479 (3) ◽  
pp. 257-274
Author(s):  
Q.M. YOU ◽  
K. ZHAO ◽  
Y.L. WANG ◽  
P. YU ◽  
J.P. KOCIOLEK ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
New Species ◽  
Central Area ◽  
Morphological Characteristics ◽  
Similar Species ◽  
Small Species ◽  
Western Sichuan ◽  
The Relationship ◽  
Scanning Electron ◽  
Apical Axis

Four new monoraphid diatoms are examined and described from a high-altitude (> 3000 m) region of western Sichuan, China.  The descriptions are based on light and scanning electron microscopy observations, and the four new species are compared with similar taxa worldwide.  Achnanthidium sichuanense sp. nov. has small, lanceolate-elliptical valves, with rounded apices. The outline and central area differentiate it from similar species.  The unique characteristic of Eucocconeis undulatum sp. nov. is that it has valves that are undulate along the apical axis, forming an “H”-shaped area on both raphe and rapheless valves as seen in light microscope (LM).  Platessa mugecuonesis sp. nov. and Platessa lanceolata sp. nov. are two small species, whose valve outlines and central areas make them different from other species in this genus.  A. sichuanense sp. nov. and E. undulatum sp. nov. are discussed in terms of the relationship between “Achnanthidium & Psammothidium” and “Eucocconeis & Psammothidium”, as these genera are difficult to separate according to morphological characteristics.

Six species of Grandidierella collected from the Ryukyu Archipelago in Japan, with descriptions of four new species (Crustacea: Amphipoda: Aoridae)

Zootaxa ◽  
2020 ◽  
Vol 4810 (1) ◽  
pp. 1-44
Author(s):  
HIROYUKI ARIYAMA
Keyword(s):  
New Species ◽  
Growth Process ◽  
Coastal Areas ◽  
The Other ◽  
Ryukyu Archipelago ◽  
Small Species ◽  
New To Japan

Six species of the amphipod genus Grandidierella Coutière, 1904 were collected from coastal areas of the Ryukyu Archipelago in Japan. Four species are new to science and the other two are new to Japan. Grandidierella contigua sp. nov. has a characteristic male gnathopod 1 with three teeth on the carpus, the proximal tooth of which is very small and contiguous with the large middle tooth. Grandidierella gilesi Chilton, 1921 is characterized by the densely setose gnathopods and the divergent merus of the gnathopod 2 in both sexes. Grandidierella halophila Wongkamhaeng, Pholpunthin & Azman, 2012 possesses a long posteromedial projection on the male coxa 2. Grandidierella japonicoides sp. nov. closely resembles G. japonica Stephensen, 1938 in having stridulating ridges on the male gnathopod 1 carpus, but the former can be distinguished from the latter in the presence of a posteromedial projection on the male coxa 2 and the shapes of the gnathopod 1 carpus in both sexes. Grandidierella nana sp. nov. is a small species and has a wide and short carpus in the male gnathopod 1. Grandidierella pseudosakaensis sp. nov. is similar to G. osakaensis Ariyama, 1996; however, the former is different from the latter in the absence of a posterodistal projection on the male gnathopod 1 ischium and the growth process of the male gnathopods. A key to Grandidierella species in the Ryukyu Archipelago is provided. 

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