Body size variation in polyplacophoran molluscs: Geographical clines and community structure along the south‐eastern Pacific

2021 ◽  
Author(s):  
Christian M. Ibáñez ◽  
Mauricio J. Carter ◽  
Moisés A. Aguilera ◽  
M. Cecilia Pardo‐Gandarillas ◽  
Enrico L. Rezende
Keyword(s):  
Community Structure ◽  
Body Size ◽  
Size Variation ◽  
Eastern Pacific ◽  
The South ◽  
Body Size Variation ◽  
South Eastern

scholarly journals Mammalian body size is determined by interactions between climate, urbanization, and ecological traits

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Maggie M. Hantak ◽  
Bryan S. McLean ◽  
Daijiang Li ◽  
Robert P. Guralnick
Keyword(s):  
Body Size ◽  
Resource Availability ◽  
Critical Role ◽  
Size Variation ◽  
Ecological Factors ◽  
Species Traits ◽  
Body Size Variation ◽  
Resource Availability Hypothesis ◽  
Urban Heat ◽  
Thermal Buffering

AbstractAnthropogenically-driven climate warming is a hypothesized driver of animal body size reductions. Less understood are effects of other human-caused disturbances on body size, such as urbanization. We compiled 140,499 body size records of over 100 North American mammals to test how climate and human population density, a proxy for urbanization, and their interactions with species traits, impact body size. We tested three hypotheses of body size variation across urbanization gradients: urban heat island effects, habitat fragmentation, and resource availability. Our results demonstrate that both urbanization and temperature influence mammalian body size variation, most often leading to larger individuals, thus supporting the resource availability hypothesis. In addition, life history and other ecological factors play a critical role in mediating the effects of climate and urbanization on body size. Larger mammals and species that utilize thermal buffering are more sensitive to warmer temperatures, while flexibility in activity time appears to be advantageous in urbanized areas. This work highlights the value of using digitized, natural history data to track how human disturbance drives morphological variation.

scholarly journals The role of local versus biogeographical processes in influencing diversity and body‐size variation in mammal assemblages

2016 ◽  
Vol 6 (5) ◽  
pp. 1447-1456 ◽  
Author(s):  
Luiz Carlos S. Lopez ◽  
Marcos S. L. Figueiredo ◽  
Maria Paula de Aguiar Fracasso ◽  
Daniel Oliveira Mesquita ◽  
Ulisses Umbelino Anjos ◽  
...  
Keyword(s):  
Body Size ◽  
Size Variation ◽  
Body Size Variation ◽  
Mammal Assemblages

Age and growth of the shortfin mako (Isurus oxyrinchus) in the south-eastern Pacific off Chile

2009 ◽  
Vol 60 (5) ◽  
pp. 394 ◽  
Author(s):  
Francisco Cerna ◽  
Roberto Licandeo
Keyword(s):  
Growth Parameters ◽  
Eastern Pacific ◽  
Age And Growth ◽  
The South ◽  
Age Classes ◽  
Vertebral Centra ◽  
South Eastern ◽  
Isurus Oxyrinchus ◽  
Shortfin Mako ◽  
Longline Fisheries

The shortfin mako, Isurus oxyrinchus, is a large pelagic shark with a widespread global distribution. However, very little is known about most aspects of this species for the south-eastern Pacific. In the present paper, the age and growth parameters of the shortfin mako, caught by Chilean swordfish longline fisheries from 2004 to 2005, are reported. Ages were estimated by counting band-pairs from sections of vertebral centra from 547 individuals, ranging from 76 to 330 cm in total length (TL). Trends in the proportion of opaque edges for all ages combined and grouped into ages 0–6 and 7–26 years indicated that they are formed during summer and showed that annually, one band-pair is formed in the vertebrae of shortfin makos. Modal-progression analysis was used to verify the first three age classes (ages 0–2 years). For both sexes, the oldest estimated age was 25+ years. Von Bertalanffy growth parameters were estimated at L∞ = 325.29 cm TL, K = 0.076 year–1 and t0 = –3.18 years for females and L∞ = 296.60 cm TL, K = 0.087 year–1 and t0 = –3.58 years for males. The results indicated that this species is highly vulnerable to exploitation and, thus, urgent conservation measures are required.

Morphometrical and molecular evidence suggests cryptic diversity among hookworms (Nematoda: Uncinaria) that parasitize pinnipeds from the south-eastern Pacific coasts

2018 ◽  
Vol 94 ◽  
Author(s):  
M.T. González ◽  
Z. López ◽  
J.J. Nuñez ◽  
K.I. Calderón-Mayo ◽  
C. Ramírez ◽  
...  
Keyword(s):  
Large Subunit ◽  
Principal Component ◽  
Eastern Pacific ◽  
Lsu Rdna ◽  
Molecular Evidence ◽  
South American ◽  
Southern Chile ◽  
The South ◽  
South Eastern ◽  
Neophoca Cinerea

AbstractHookworms of the genus Uncinaria parasitize pinniped pups in various locations worldwide. Four species have been described, two of which parasitize pinniped pups in the southern hemisphere: Uncinaria hamiltoni parasitizes Otaria flavescens and Arctocephalus australis from the South American coast, and Uncinaria sanguinis parasitizes Neophoca cinerea from the Australian coast. However, their geographical ranges and host specificity are unknown. Uncinaria spp. are morphologically similar, but molecular analyses have allowed the recognition of new species in the genus Uncinaria. We used nuclear genetic markers (internal transcribed spacer (ITS) and large subunit (LSU) rDNA) and a mitochondrial genetic marker (cytochrome c oxidase subunit I (COI)) to evaluate the phylogenetic relationships of Uncinaria spp. parasitizing A. australis and O. flavescens from South American coasts (Atlantic and Pacific coasts). We compared our sequences with published Uncinaria sequences. A Generalized Mixed Yule Coalescent (GMYC) analysis was also used to delimit species, and principal component analysis was used to compare morphometry among Uncinaria specimens. Parasites were sampled from A. australis from Peru (12°S), southern Chile (42°S), and the Uruguayan coast, and from O. flavescens from northern Chile (24°S) and the Uruguayan coast. Morphometric differences were observed between Uncinaria specimens from both South American coasts and between Uncinaria specimens from A. australis in Peru and southern Chile. Phylogenetic and GMYC analyses suggest that south-eastern Pacific otariid species harbour U. hamiltoni and an undescribed putative species of Uncinaria. However, more samples from A. australis and O. flavescens are necessary to understand the phylogenetic patterns of Uncinaria spp. across the South Pacific.

scholarly journals Insights into body size variation in cetaceans from the evolution of body-size-related genes

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yingying Sun ◽  
Yanzhi Liu ◽  
Xiaohui Sun ◽  
Yurui Lin ◽  
Daiqing Yin ◽  
...  
Keyword(s):  
Body Size ◽  
Size Variation ◽  
Body Size Variation
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