scholarly journals Seasonal and Ontogenetic Variation in Depth Use by a Critically Endangered Benthic Elasmobranch and Its Implications for Spatial Management

2021 ◽  
Vol 8 ◽  
Author(s):  
James Thorburn ◽  
Peter J. Wright ◽  
Edward Lavender ◽  
Jane Dodd ◽  
Francis Neat ◽  
...  
Keyword(s):  
Body Size ◽  
Critically Endangered ◽  
Ontogenetic Variation ◽  
Depth Range ◽  
Depth Data ◽  
Spatial Management ◽  
Additive Mixed Models ◽  
Entire Depth ◽  
Time Of Year ◽  
Depth Use

Seasonal and ontogenetic variations in depth use by benthic species are often concomitant with changes in their spatial distribution. This has implications for the efficacy of spatial conservation measures such as marine protected areas (MPAs). The critically endangered flapper skate (Dipturus intermedius) is the designation feature of an MPA in Scotland. This species is generally associated with deeper waters >100 m; however, little is known about its seasonal or ontogenetic variation in habitat use. This study used archival depth data from 25 immature and mature flapper skate tagged in the MPA over multiple years. Time series ranged from 3 to 772 (mean = 246) days. Generalised additive mixed models and highest density intervals were used to identify home (95%) and core (50%) highest density depth regions (HDDRs) to quantify depth use in relation to time of year and body size. Skate used a total depth range of 1–312 m, but home HDDRs typically occurred between 20 and 225 m. Core HDDRs displayed significant seasonal and ontogenetic variations. Summer core HDDRs (100–150 m) suggest high occupancy of the deep trenches in the region by skate of most size classes. There was an inverse relationship between body size and depth use and a seasonal trend of skate moving into shallow water over winter months. These results suggest that flapper skate are not solely associated with deep water, as skate, especially large females, are frequently found in shallow waters (25–75 m). The current management, which protects the entire depth range, is appropriate for the protection of flapper skate through much of its life history. This research demonstrates why collecting data across seasonal scales and multiple ontogenetic stages is needed to assess the effectiveness of spatial management.

scholarly journals Threatened birds of Guatemala: a random subset of the avifauna?

2011 ◽  
Vol 22 (3) ◽  
pp. 348-353
Author(s):  
ANDREA NÁJERA ◽  
JAVIER A. SIMONETTI
Keyword(s):  
Body Size ◽  
Geographical Distribution ◽  
Scientific Information ◽  
Bird Species ◽  
Critically Endangered ◽  
Aquatic Species ◽  
Random Subset ◽  
The Pacific ◽  
Taxonomic Affiliation

SummaryIdentifying attributes that affect the vulnerability of a species to extinction is important as it allows conservation efforts to be focused on more susceptible species. We assessed whether threatened birds of Guatemala are a random subset of the avifauna, considering their taxonomic affiliation, body size, diet and geographical distribution. We found that threatened bird species in Guatemala were neither taxonomically nor geographically randomly distributed. Large-bodied species and Psittaciformes, Galliformes, Falconiformes and Ciconiformes were among the most threatened groups, and the Pacific slopes of the country hosted more threatened birds than would be expected. Published scientific information regarding Critically Endangered bird species in Guatemala is scant and biased against nocturnal and aquatic species. Research and conservation efforts ought to be oriented toward these species and regions to safeguard the Guatemalan avifauna. This study allows an overall consideration on whether we are conserving the species and areas that are important for threatened birds.

A new skink fauna from Caribbean islands (Squamata, Mabuyidae, Mabuyinae)

Zootaxa ◽  
2012 ◽  
Vol 3288 (1) ◽  
pp. 1 ◽  
Author(s):  
S. BLAIR HEDGES ◽  
CAITLIN E. CONN
Keyword(s):  
Body Size ◽  
South America ◽  
Reproductive Traits ◽  
Morphological Characters ◽  
Critically Endangered ◽  
Glacial Cycles ◽  
Critically Endangered Species ◽  
Caribbean Islands ◽  
Island Species ◽  
Degree Of Convergence

Neotropical skinks are unique among lizards and other vertebrates in their degree of convergence, in reproductive traits,with eutherian mammals. They have also been famously difficult to classify into species, largely because of a conservativebody plan and paucity of conventional diagnostic characters. Currently there are 26 recognized species, six of which occuronly on Caribbean islands. All are placed in a single genus, Mabuya. We conducted a systematic revision of Neotropicalskinks using both conventional and unconventional morphological characters, supplemented by DNA sequence analyses.We define 61 species grouped into 16 clades, recognized here as genera. They include three available generic names(Copeoglossum, Mabuya, and Spondylurus) and 13 new genera: Alinea gen. nov., Aspronema gen. nov., Brasiliscincusgen. nov., Capitellum gen. nov., Exila gen. nov., Manciola gen. nov., Maracaiba gen. nov., Marisora gen. nov., Noto-mabuya gen. nov., Orosaura gen. nov., Panopa gen. nov., Psychosaura gen. nov., and Varzea gen. nov. These 16 generaof skinks form a monophyletic group and are placed in the Subfamily Mabuyinae of the skink Family Mabuyidae. Sixother skink families are recognized: Acontidae, Egerniidae, Eugongylidae, Lygosomidae, Scincidae, and Sphenomorphi-dae. We describe three new subfamilies of Mabuyidae: Chioniniinae subfam. nov., Dasiinae subfam. nov., and Trachyl-epidinae subfam. nov. We describe 24 new species of mabuyines: Capitellum mariagalantae sp. nov., Capitellumparvicruzae sp. nov., Copeoglossum aurae sp. nov., Copeoglossum margaritae sp. nov., Copeoglossum redondae sp.nov., Mabuya cochonae sp. nov., Mabuya desiradae sp. nov., Mabuya grandisterrae sp. nov., Mabuya guadeloupae sp.nov., Mabuya hispaniolae sp. nov., Mabuya montserratae sp. nov., Marisora aurulae sp. nov., Marisora magnacornaesp. nov., Marisora roatanae sp. nov., Spondylurus anegadae sp. nov., Spondylurus culebrae sp. nov., Spondylurus caico-sae sp. nov., Spondylurus haitiae sp. nov., Spondylurus magnacruzae sp. nov., Spondylurus martinae sp. nov., Spondy-lurus monae sp. nov., Spondylurus monitae sp. nov., Spondylurus powelli sp. nov., and Spondylurus turksae sp. nov. Wealso resurrect 10 species from synonymies: Alinea lanceolata comb. nov., Alinea luciae comb. nov., Capitellum metalli-cum comb. nov., Mabuya dominicana, Marisora alliacea comb. nov., Marisora brachypoda comb. nov., Spondylurusfulgidus comb. nov., Spondylurus nitidus comb. nov., Spondylurus semitaeniatus comb. nov., and Spondylurus spilonotuscomb. nov. Of the 61 total species of mabuyine skinks, 39 occur on Caribbean islands, 38 are endemic to those islands,and 33 of those occur in the West Indies. Most species on Caribbean islands are allopatric, single-island endemics, al-though three species are known from Hispaniola, three from St. Thomas, and two from Culebra, St. Croix, Salt Island,Martinique, the southern Lesser Antilles, Trinidad, and Tobago. Co-occurring species typically differ in body size and be-long to different genera. Three ecomorphs are described to account for associations of ecology and morphology: terrestri-al, scansorial, and cryptozoic. Parturition occurs at the transition between the dry and wet seasons, and the number ofyoung (1–7) is correlated with body size and taxonomic group. Molecular phylogenies indicate the presence of many un-named species in Middle and South America. A molecular timetree shows that mabuyines dispersed from Africa to SouthAmerica 18 (25–9) million years ago, and that diversification occurred initially in South America but soon led to coloni-zation of Caribbean islands and Middle America. The six genera present on Caribbean islands each represent separate dis-persals, over water, from the mainland during the last 10 million years. Considerable dispersal and speciation alsooccurred on and among Caribbean islands, probably enhanced by Pleistocene glacial cycles and their concomitant sea lev-el changes. Based on IUCN Redlist criteria, all of the 38 endemic Caribbean island species are threatened with extinction.Twenty-seven species (71%) are Critically Endangered, six species (16%) are Endangered, and five species (13%) are Vul-nerable. Sixteen of the Critically Endangered species are extinct, or possibly extinct, because of human activities duringthe last two centuries. Several of the surviving species are near extinction and in need of immediate protection. Analysisof collection records indicates that the decline or loss of 14 skink species can be attributed to predation by the Small IndianMongoose. That invasive predator was introduced as a biological control of rats in sugar cane fields in the late nineteenthcentury (1872–1900), immediately resulting in a mass extinction of skinks and other reptiles. The ground-dwelling and diurnal habits of skinks have made them particularly susceptible to mongoose predation.

scholarly journals Parasite biodiversity and its determinants in coastal marine teleost fishes of Brazil

Parasitology ◽  
2004 ◽  
Vol 128 (6) ◽  
pp. 671-682 ◽  
Author(s):  
J. L. LUQUE ◽  
D. MOUILLOT ◽  
R. POULIN
Keyword(s):  
Species Richness ◽  
Body Size ◽  
Parasite Species ◽  
Feeding Habits ◽  
Taxonomic Distinctness ◽  
Depth Range ◽  
Metazoan Parasites ◽  
Parasite Species Richness ◽  
Parasite Biodiversity ◽  
Parasite Assemblages

Recent studies of the forces behind the diversification of parasite assemblages have shed light on many aspects of parasite biodiversity. By using only parasite species richness as their measure of diversity, however, previous investigations have ignored the relatedness among parasite species and the taxonomic structure of the assemblages, which contain much information about their evolutionary origins. Here, we performed a comparative analysis across 50 species of fish from the coast of Brazil; we evaluated the effects of several host traits (body size, social behaviour, feeding habits, preference for benthicvs. pelagic habitats, depth range, and ability to enter brackish waters) on the diversity of their assemblages of metazoan parasites. As measures of diversity, we used parasite species richness, as well as the average taxonomic distinctness of the assemblage and its variance; the latter measures are based on the average taxonomic distance between any two parasite species in an assemblage. Unlike parasite species richness, taxonomic distinctness was unaffected by the number of host individuals examined per species. Fish body length proved to be the main predictor of parasite species richness, even when controlling for the confounding influences of host phylogeny and sampling effort, although it did not correlate with measures of parasite taxonomic distinctness. Predatory fish also had higher parasite species richness than planktivores, but this trend could not be confirmed using phylogenetically independent contrasts between host taxa. The main host feature associated with the taxonomic diversity of parasites was schooling behaviour, with schooling fish having more taxonomically diverse parasite assemblages than those of their non-schooling relatives. When focusing on endoparasite species only, both predatory feeding habits and a broad depth range were associated with the taxonomic distinctness of parasites. Our results suggest that certain host traits (i.e. body size) determine how many parasite species a host can accumulate over evolutionary time, whereas different host features influence the processes causing the taxonomic diversification of parasite assemblages.

scholarly journals Ontogenetic Variation in Movements and Depth Use, and Evidence of Partial Migration in a Benthopelagic Elasmobranch

2019 ◽  
Vol 7 ◽  
Author(s):  
James Thorburn ◽  
Francis Neat ◽  
Ian Burrett ◽  
Lea-Anne Henry ◽  
David M. Bailey ◽  
...  
Keyword(s):  
Partial Migration ◽  
Ontogenetic Variation ◽  
Depth Use

Reproductive pattern and sexual system of the nocturnal seagrass shrimp Ambidexter symmetricus (Decapoda: Caridea: Processidae) in a Florida bay

2016 ◽  
Vol 67 (8) ◽  
pp. 1141
Author(s):  
Jennifer A. Rasch ◽  
Raymond T. Bauer
Keyword(s):  
Body Size ◽  
Benthic Invertebrates ◽  
Late Stage ◽  
Population Biology ◽  
Reproductive Pattern ◽  
Sexual System ◽  
Seasonal Differences ◽  
Time Of Year ◽  
Marine Benthic Invertebrates ◽  
Warm Temperate

The purpose of the current study was to analyse the reproductive ecology and sexual system in Ambidexter symmetricus (Processidae), a nocturnal seagrass shrimp. This work was conducted in St Joseph Bay, Florida, in May–August 2010 and April–October 2011. The sex ratio in A. symmetricus and the presence of juvenile females supported the hypothesis of a gonochoric sexual system. Breeding in the population occurred seasonally from April until September. Successive spawning of individual females was shown by the presence of late-stage (prespawning) ovaries in females that were brooding late-stage (near hatching) embryos. Female A. symmetricus were generally larger and more abundant than males. Male A. symmetricus with parasites exhibited gigantism. Because of seasonal differences in recruitment and growth, body size varied with time of year, with larger (overwintered) individuals collected in April and May, and smaller more recently recruited individuals more abundant in September and October. The population biology of this species is similar to many other warm-temperate, shallow-water carideans, thus supporting hypotheses about latitudinal variation in breeding and recruitment in marine benthic invertebrates.

Shape Measurement of Solder Bumps by Shape-from-Focus Using Varifocal Mirror

2006 ◽  
Vol 18 (6) ◽  
pp. 722-727
Author(s):  
Jun Mitsudo ◽  
◽  
Akira Ishii
Keyword(s):  
Copper Alloy ◽  
Solder Bump ◽  
Optical Axis ◽  
Focal Point ◽  
Shape Measurement ◽  
Depth Range ◽  
Focal Points ◽  
Depth Data ◽  
Solder Bumps ◽  
Shape From Focus

We measured solder bumps on an LSI package board presented for inspection based on the shape from focus. We used a copper-alloy mirror deformed by a piezoelectric actuator as a varifocal mirror to build a motionless yet fast focusing mechanism. The varifocal mirror was at the image focal point of the image-taking lens so that lateral magnification was constant during focusing and orthographic projection was established. A focused plane was shifted along the optical axis with a precision of 1.4μm in a depth range of 1.5mm by driving the varifocal mirror. A magnification of 1.97 was maintained during focusing. Evaluating the curvature of field and removing its effect from the depth data reduced errors. The shape of 208 solder bumps 260-μm high spaced 500μm on the board was measured. The 10mm×10mm board was segmented into partly overlapping 3×4 sections. We captured 101 images in each section with a high-resolution camera at different focal points at 15-μm intervals. The shape of almost the entire upper-hemisphere of a solder bump could be measured. Error in measuring bump heights was less than 12μm.

Chromosomal diversity in tropical reef fishes is related to body size and depth range

2015 ◽  
Vol 93 ◽  
pp. 1-4 ◽  
Author(s):  
P.A. Martinez ◽  
J.P. Zurano ◽  
T.F. Amado ◽  
C. Penone ◽  
R. Betancur-R ◽  
...  
Keyword(s):  
Body Size ◽  
Reef Fishes ◽  
Depth Range ◽  
Tropical Reef

The effect of drought on body size, growth and abundance of wild brush-tailed phascogales (Phascogale tapoatafa) in south-western Australia

2002 ◽  
Vol 29 (3) ◽  
pp. 235 ◽  
Author(s):  
S. G. Rhind ◽  
J. S. Bradley
Keyword(s):  
Body Size ◽  
Western Australia ◽  
Population Decline ◽  
Adult Males ◽  
Growth Data ◽  
The South ◽  
Nest Boxes ◽  
South West ◽  
Size Growth ◽  
Time Of Year

Body size and growth data were gathered on 387 wild brush-tailed phascogales captured between 1992–1997 in south-western Australia. This marsupial has not previously been studied in Western Australia. Compared with Victorian phascogales, those in the south-west (single region) are typically 20–30% smaller in mass, smaller in skeletal measurements, and sexual size dimorphism is less. Habitat quality was correlated with body size and the largest phascogales were found in swamp/gully systems. These findings suggest food is a normally limiting resource for this species in the south-west environment. Additionally, a significant decrease in growth and size occurred during a drought year (1994), and growth of young seemed restricted during dependency. Maternal mortality appeared high during late lactation as orphaned, unweaned young were encountered in nest boxes. In 1995 adult males were 25% less in mass than usual; females 15% less. Population decline followed and by 1996 capture rates were 1/3 of that typically found for the time of year. Recovery was not apparent until two years after drought (early 1997). In this food-limited environment phascogale populations appear particularly vulnerable to annual fluctuations in rainfall.

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