scholarly journals Adult life strategy affects distribution patterns in abyssal isopods – implications for conservation in Pacific nodule areas

2020 ◽  
Vol 17 (23) ◽  
pp. 6163-6184
Author(s):  
Saskia Brix ◽  
Karen J. Osborn ◽  
Stefanie Kaiser ◽  
Sarit B. Truskey ◽  
Sarah M. Schnurr ◽  
...  
Keyword(s):  
Species Composition ◽  
Adult Life ◽  
Manganese Nodule ◽  
Distribution Patterns ◽  
Species Range ◽  
Integrative Approach ◽  
Life Strategy ◽  
Central Pacific ◽  
Species Ranges ◽  
Sea Bed

Abstract. With increasing pressure to extract minerals from the deep-sea bed, understanding the ecological and evolutionary processes that limit the spatial distribution of species is critical to assessing ecosystem resilience to mining impacts. The aim of our study is to gain a better knowledge about the abyssal isopod crustacean fauna of the central Pacific manganese nodule province (Clarion–Clipperton Fracture Zone, CCZ). In total, we examined 22 epibenthic sledge (EBS) samples taken at five abyssal areas located in the central northern Pacific including four contracting areas and one Area of Particular Environmental Interest (APEI3). Additional samples come from the DISturbance and reCOLonization experiment (DISCOL) area situated in the Peru Basin, southeastern Pacific. Using an integrative approach that combined morphological and genetic methods with species delimitation analyses (SDs) we assessed patterns of species range size, diversity, and community composition for four different isopod families (Munnopsidae Lilljeborg, 1864; Desmosomatidae Sars, 1897; Haploniscidae Hansen, 1916; and Macrostylidae Hansen, 1916) displaying different dispersal capacities as adults. Isopods are brooders, so their distribution and connectivity cannot be explained by larval dispersal but rather by adult locomotion. In particular, our objectives were to (1) identify potential differences in the distributional ranges of isopod families relative to their locomotory potential and to (2) evaluate the representativeness of the APEI for the preservation of regional biodiversity in the CCZ following mining disturbances. From 619 specimens, our SD analysis could distinguish 170 species, most of which were new to science (94.1 %). We found that increased locomotory ability correlated with higher species diversity with 9 species of Macrostylidae, 23 of Haploniscidae, 52 of Desmosomatidae, and 86 of Munnopsidae. This is supported by family-level rarefaction analyses. As expected, we found the largest species ranges in the families with swimming abilities, with a maximum recorded species range of 5245 and 4480 km in Munnopsidae and Desmosomatidae, respectively. The less motile Haploniscidae and Macrostylidae had maximal species ranges of 1391 and 1440 km, respectively. Overall, rarefaction analyses indicated that species richness did not vary much between areas, but the real number of species was still not sufficiently sampled. This is also indicated by the large proportion of singletons (40.5 %) found in this study. The investigated contractor areas in the CCZ were more similar in species composition and had a higher proportion of shared species between each other than the closely located APEI3 and the distantly located DISCOL area. In fact, the DISCOL area, located in the Peru Basin, had more species in common with the core CCZ areas than APEI3. In this regard, APEI3 does not appear to be representative as serving as a reservoir for the fauna of the investigated contractor areas, at least for isopods, as it has a different species composition. Certainly, more data from other APEIs, as well as preservation reference zones within contractor areas, are urgently needed in order to assess their potential as resources of recolonization of impacted seabed.

scholarly journals Adult life strategy affects distribution patterns in abyssal isopods – implications for conservation in Pacific nodule areas

2019 ◽  
Author(s):  
Saskia Brix ◽  
Karen J. Osborn ◽  
Stefanie Kaiser ◽  
Sarit B. Truskey ◽  
Sarah M. Schnurr ◽  
...  
Keyword(s):  
Adult Life ◽  
Manganese Nodule ◽  
Specific Area ◽  
Distribution Patterns ◽  
Common Species ◽  
Life Strategy ◽  
Central Pacific ◽  
Central Pacific Ocean ◽  
Number Of Species ◽  
Clarion Clipperton Fracture Zone

Abstract. Aim of our study is to gain a better knowledge about the isopod crustacean fauna of the abyssal Clarion Clipperton Fracture Zone (CCZ) located in the central Pacific Ocean. In total, we examined 22 EBS samples taken at 6 abyssal areas in the central pacific manganese nodule area (CCZ and DISCOL). The dataset comprised 619 specimens belonging to 187 species of four different isopod families: 91 species (48.6 % of total) belonging to Munnopsidae, 63 (33.6 %) to Desmosomatidae, 24 (12.8 %) to Haploniscidae and 9 (4.8 %) to Macrostylidae. The total number of species found was relatively similar between sites ranging from 38 (German Contractor area) to 50 species (French contractor area). 68 species were represented by singeletons. The ranges of distribution differ between families. In total 77 % of the species were recorded in a single area (and thus being unique for this specific area), 13.9 % in 2 areas, 5.3 % in 3 areas, 2.6 % in 4 areas and 1 % in 5 areas. The proportion of species present in a single area increased in this sequence: Munnopsidae (75.8 %), Desmosomatidae (77.7 %) and Haploniscidae (83 %). A total of 6 (66.6 %) out of 9 species of Macrostylidae was recorded in a single area contrasted by the most common species being from this family, Macrostylidae_Macrostylis_M05 with 46 specimens (present in all areas besides DISCOL) followed by several species of Munnopsidae with 10 or more specimens in the dataset. The CCZ areas show the highest number of shared species. Generally, the high diversity in each area is reflected by a low similarity between sampling areas. The rarefraction curves indicate that species richness is similar between areas, but the real number of species is still not sampled. The most distant areas from the central CCZ, the APEI3 and DISCOL, are the most different.

The germinable soil seedbank of Eucalyptus victrix grassy woodlands at Roy Hill station, Pilbara district, Western Australia

2004 ◽  
Vol 26 (1) ◽  
pp. 17 ◽  
Author(s):  
R. A. Graham ◽  
S. K. Florentine ◽  
J. E. D. Fox ◽  
T. M. Luong
Keyword(s):  
Species Composition ◽  
Western Australia ◽  
Perennial Grass ◽  
Summer Rainfall ◽  
Distribution Patterns ◽  
Grass Species ◽  
Surface Areas ◽  
Hill Station ◽  
Soil Seedbank ◽  
Germinable Seed

The paper reports soil seedbank species composition, of Eucalyptus victrix grassy woodlands, of the upper Fortescue River in the Pilbara District, Western Australia. In this study, our objectives were to investigate germinable soil seedbanks and species composition in response to three simulated seasons, using emergence. Variation in seed density from three depths was tested. Four field sites were sampled. Thirty samples were collected in late spring, after seed rain and before summer rainfall. From each sample spot, three soil depths (surface, 1–5, and 6–10 cm) were segregated from beneath surface areas of 100 cm2. Samples were later incubated in a glasshouse to simulate three different seasonal conditions (autumn, winter and spring). Germinating seedlings were recorded on emergence and grown until identified. Forty-one species germinated, comprising 11 grasses (7 annuals and 4 perennials), 25 annual herbs and 5 perennial herbs. Distribution patterns of germinable seed in both the important annual grass Eragrostis japonica and the perennial Eragrostis setifolia (a preferred cattle fodder species), suggest that seedbank accumulation differs among species and between sites. In part, this may be associated with the absence of grazing. Species with most total germinable seed were E. japonica (Poaceae; 603/m2), and the annual herbs Calotis multicaulis (Asteraceae; 346/m2), and Mimulus gracilis (Scrophulariaceae; 168/m2). Perennial grass seed was sparse. Spring simulation gave most germination (1059), followed by autumn (892) and winter (376) sets. Greatest species diversity was produced from the spring simulation (33 species), followed by autumn (26), and winter (22). Of the total germination, 92% came from 17 species that were represented in all three simulations. Of the 1227 grass seedlings counted, most were recruited from the surface soil (735), followed by the 5 (310) and 10 (182) cm depths. Marginally more grass seedlings germinated from the spring simulation (558) than the autumn set (523). Only 11.9% of grass germinants came from the winter simulation. All grass species recruited from the soil seedbanks had a C4 photosynthetic pathway. Except for Cenchrus ciliaris all grass species are native to Australia. Of the four sites sampled, one fenced to exclude cattle five years earlier had significantly more germination than the three unfenced sites. Seedbank sampling produced several new records for plants in the areas sampled.

Distribution of moss-inhabiting diatoms along an altitudinal gradient at sub-Antarctic Îles Kerguelen

2007 ◽  
Vol 19 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Niek J.M. Gremmen ◽  
Bart van de Vijver ◽  
Yves Frenot ◽  
Marc Lebouvier
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Altitudinal Gradient ◽  
Cross Validation ◽  
Strong Relationship ◽  
Distribution Patterns ◽  
Common Species ◽  
Important Variable ◽  
Diatom Species ◽  
Expected Species Richness

Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.

scholarly journals Higher Variability in Fungi Compared to Bacteria in the Foraging Honey Bee Gut

2020 ◽  
Author(s):  
Leslie E. Decker ◽  
Priscilla A. San Juan ◽  
Magdalena L. Warren ◽  
Cory E. Duckworth ◽  
Cheng Gao ◽  
...  
Keyword(s):  
Species Composition ◽  
Microbial Communities ◽  
Honey Bee ◽  
Honey Bees ◽  
Plant Pathogens ◽  
Distribution Patterns ◽  
Model System ◽  
Pathogen Transmission ◽  
Host Health ◽  
Gut Symbionts

AbstractMicrobial communities in the honey bee gut have emerged as a model system to understand the effects of host-associated microbes on animals and plants. The specific distribution patterns of bacterial associates among honey bee gut regions remains a key finding within the field. The mid- and hindgut of foraging bees house a deterministic set of core species that affect host health. In contrast, the crop, or honey stomach, contains a more diverse set of bacteria that is highly variable in composition among individual bees. Whether this contrast between the two gut regions also applies to fungi, another major group of gut-associated microbes, remains unclear despite their potential influence on host health. In honey bees caught foraging at four sites across the San Francisco Peninsula, we found that fungi were much less distinct in species composition between the crop and the mid- and hindgut than bacteria. Unlike bacteria, fungi were highly variable in composition throughout the gut, and much of this variation was attributable to bee collection site. These patterns suggest that the fungi may be passengers rather than functionally significant gut symbionts. However, many of the fungi we found in the bees have been recognized as plant pathogens. Assuming that some fungi remain viable after passage through the gut, the distribution patterns we report here point to the potential importance of honey bees as vectors of fungal pathogens and suggest a more prominent role of honey bees in plant pathogen transmission than generally thought.Importance (Nontechnical explanation of why the work was undertaken)Along with bacteria, fungi make up a significant portion of animal- and plant-associated microbial communities. However, we have only begun to describe these fungi, much less examine their effects on most animals and plants. The honey bee, Apis mellifera, has emerged as a model system for studying host-associated microbes. Honey bees contain well-characterized bacteria specialized to inhabit different regions of the gut. Fungi also exist in the honey bee gut, but their composition and function remain largely undescribed. Here we show that, unlike bacteria, fungi vary substantially in species composition throughout the honey bee gut, contingent on where the bees are sampled. This observation suggests that fungi may be transient passengers and therefore unimportant as gut symbionts. However, our findings also indicate that honey bees could be major vectors of infectious plant diseases as many of the fungi we found in the honey bee gut are recognized as plant pathogens.

A preliminar overview of species composition and geographical distribution of Malvinian weevils (Insecta: Coleoptera: Curculionidae)

Zootaxa ◽  
2008 ◽  
Vol 1704 (1) ◽  
pp. 1 ◽  
Author(s):  
PAULA POSADAS
Keyword(s):  
South America ◽  
Species Composition ◽  
Tierra Del Fuego ◽  
Integrative Approach ◽  
Generic Level ◽  
Distributional Information ◽  
Sea Level Variations ◽  
Islas Malvinas ◽  
High Degree ◽  
Very High

The objective of this paper is to provide an integrative approach to species composition and distributional information on the weevil fauna of Islas Malvinas (Falkland Islands). A total of 22 species belonging to 11 Curculionidae genera are recorded for the archipelago. Four of these genera belong to Entiminae (i.e., Caneorhinus, Cylydrorhinus, Malvinius, and Morronia) and the remaining seven belong to Cyclominae (i.e., Antarctobius, Falklandiellus, Falklandius, Germainiellus; Haversiella, Lanteriella, and Puranius). The Malvinian weevil fauna could be considered as an impoverished version of that from Tierra del Fuego at the generic level, but with a very high degree of species level endemism. The Malvinian weevil fauna exhibits a great linkage to that from southernmost South America. It has been postulated that the evolution of Malvinian weevil fauna responded to several geodispersal and subsequent vicariant events which determined the archipelago´s alternative connections and disconnections from southern South America. These events were due to sea-level variations induced by glacial-eustatic agents during Tertiary and Quaternary times. Finally, synonymic lists are provided for each species known to occur on the islands. Also, distributional data for each species are mapped and keys and illustrations are presented to identify weevil taxa recorded for the Islas Malvinas.

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