This study examined the dispersal abilities, population structure, and performance of two Cape Xenopus frog species: X. gilli and X. laevis. The results show that X. laevis has greater jumping and swimming performance. X. laevis also dispersed farther and more frequently. Analysis of skeletal growth layers was not effective for aging Cape Xenopus. Survival rates of X. gilli were lower at sites where it co-occurred with X. laevis, suggesting a negative impact of X. laevis on X. gilli. The results provide evidence that X. laevis poses a threat to X. gilli through competition and potential hybridization.
Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) ...Sana_haroon
this is my presentation based on research paper title "Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) from the Gulf of Suez, Red Sea, Egypt"
This was written by Amgad M. Shaaban et al., 2018
Which have Impact factor: 1.98
Lamarck's theory of evolution proposed that acquired characteristics could be inherited, such as giraffes developing longer necks due to stretching to reach leaves. Darwin later established the theory of evolution by natural selection, whereby favorable variations or adaptations are preserved and passed on during reproduction, while unfavorable traits are selected against. Evidence for evolution includes fossils that show gradual changes in organisms over time, as well as anatomical, embryological, and molecular similarities between different species.
This study examined the morphometric and meristic characters of the fish Channa punctatus in the Indus River in Pakistan. 200 fish specimens were measured for 11 body parts and scales/fin counts were also taken. Regression analysis found strong correlations between total length and other body parts. Most measurements were found to increase linearly with total length. Meristic counts were also consistent between males and females. This baseline data on the physical traits of this commercially important fish will help with future cultivation efforts.
This document discusses using the nematode C. elegans as a model organism to uncover the genetic basis of natural variation in behavior and development. Key points:
1) C. elegans exhibits diverse behaviors and phenotypes in the wild that can be quantified using high-throughput tracking of locomotion features in response to stimuli like CO2.
2) Machine learning techniques like Iterative Denoising Trees are used to reduce the dimensionality of time-series behavior data from many wild C. elegans strains into distinct behavioral profiles.
3) Genome sequencing of wild strains reveals genetic variation that can be tested for association with behavioral profiles using methods like MURAT to identify candidate genes underlying natural phenotypic differences.
Ndour et al., 2013. Reproduction of Mugil cephalusIsmaila Ndour
1) The study examined the reproductive parameters of the yellow mullet (Mugil cephalus) on the Northern Coast of Senegal between 2010-2012. 2) It found that the gonadosomatic index and sexual maturity stages peaked in December and January, indicating spawning likely begins in December and is complete by June. 3) The size at first sexual maturity was estimated to be 39 cm for males and 42 cm for females.
Investigation of otolith in Priacanthus tayenusin persian gulf and Oman SeaInnspub Net
This study aimed to investigation of otolith in Priacanthus tayenusin Persian Gulf and Oman Sea. Sampling lasted from September 2011 to December 2012. During this period 5 samples of Priacanthus tayenus were cut
and studied. Trawling time was 2-2½ hours and trawling depth was considered as 10-100 m daily. Catching and
sampling operations was done within 24 hours. Sampling and catching was done in Khuzestan and Bushehr waters in fall and winter of 2011and since the third week of September 2012 sampling was done in Hormozgan
and Sistan and Baloochestan waters. All thefish were identified and their otolith was extracted to verify them.
Investigation of otolith morphometric characteristics (length, breadth, weight, perimeter and area) were
conducted.
Effect of Stocking Density on the Resistance to Fasting, Growth and Survival ...Agriculture Journal IJOEAR
Abstract— After artificial reproduction of African catfish Heterobranchus bidorsalis, larvae of two days old and 2.18 ± 0.35 mg of mean weight were used to perform two experiments in order to assess the effect of stocking density on their fasting resistance, growth and survival. During the first experiment which lasted 11 days with four batches of larvae at densities of 1, 2, 3 and 4 individuals/ml, results showed that density did not significantly affect (p˂0,05) the resistance to fasting of larvae. However, first mortalities were observed at D5 for all the densities, the higher daily mortality was recorded at D10 and the last mortalities were obtained at D12.
Results of the second experiment revealed that the weight and growth performance of larvae decreased with the increasing of the density after 28 days of rearing. In contrast, the larval survival rate increased with the density. The values of survival rate were respectively 30.53 ± 4.32 and 55.30 ± 21.70 % for the densities 1 ind./l and 20 ind./l.
Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) ...Sana_haroon
this is my presentation based on research paper title "Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) from the Gulf of Suez, Red Sea, Egypt"
This was written by Amgad M. Shaaban et al., 2018
Which have Impact factor: 1.98
Lamarck's theory of evolution proposed that acquired characteristics could be inherited, such as giraffes developing longer necks due to stretching to reach leaves. Darwin later established the theory of evolution by natural selection, whereby favorable variations or adaptations are preserved and passed on during reproduction, while unfavorable traits are selected against. Evidence for evolution includes fossils that show gradual changes in organisms over time, as well as anatomical, embryological, and molecular similarities between different species.
This study examined the morphometric and meristic characters of the fish Channa punctatus in the Indus River in Pakistan. 200 fish specimens were measured for 11 body parts and scales/fin counts were also taken. Regression analysis found strong correlations between total length and other body parts. Most measurements were found to increase linearly with total length. Meristic counts were also consistent between males and females. This baseline data on the physical traits of this commercially important fish will help with future cultivation efforts.
This document discusses using the nematode C. elegans as a model organism to uncover the genetic basis of natural variation in behavior and development. Key points:
1) C. elegans exhibits diverse behaviors and phenotypes in the wild that can be quantified using high-throughput tracking of locomotion features in response to stimuli like CO2.
2) Machine learning techniques like Iterative Denoising Trees are used to reduce the dimensionality of time-series behavior data from many wild C. elegans strains into distinct behavioral profiles.
3) Genome sequencing of wild strains reveals genetic variation that can be tested for association with behavioral profiles using methods like MURAT to identify candidate genes underlying natural phenotypic differences.
Ndour et al., 2013. Reproduction of Mugil cephalusIsmaila Ndour
1) The study examined the reproductive parameters of the yellow mullet (Mugil cephalus) on the Northern Coast of Senegal between 2010-2012. 2) It found that the gonadosomatic index and sexual maturity stages peaked in December and January, indicating spawning likely begins in December and is complete by June. 3) The size at first sexual maturity was estimated to be 39 cm for males and 42 cm for females.
Investigation of otolith in Priacanthus tayenusin persian gulf and Oman SeaInnspub Net
This study aimed to investigation of otolith in Priacanthus tayenusin Persian Gulf and Oman Sea. Sampling lasted from September 2011 to December 2012. During this period 5 samples of Priacanthus tayenus were cut
and studied. Trawling time was 2-2½ hours and trawling depth was considered as 10-100 m daily. Catching and
sampling operations was done within 24 hours. Sampling and catching was done in Khuzestan and Bushehr waters in fall and winter of 2011and since the third week of September 2012 sampling was done in Hormozgan
and Sistan and Baloochestan waters. All thefish were identified and their otolith was extracted to verify them.
Investigation of otolith morphometric characteristics (length, breadth, weight, perimeter and area) were
conducted.
Effect of Stocking Density on the Resistance to Fasting, Growth and Survival ...Agriculture Journal IJOEAR
Abstract— After artificial reproduction of African catfish Heterobranchus bidorsalis, larvae of two days old and 2.18 ± 0.35 mg of mean weight were used to perform two experiments in order to assess the effect of stocking density on their fasting resistance, growth and survival. During the first experiment which lasted 11 days with four batches of larvae at densities of 1, 2, 3 and 4 individuals/ml, results showed that density did not significantly affect (p˂0,05) the resistance to fasting of larvae. However, first mortalities were observed at D5 for all the densities, the higher daily mortality was recorded at D10 and the last mortalities were obtained at D12.
Results of the second experiment revealed that the weight and growth performance of larvae decreased with the increasing of the density after 28 days of rearing. In contrast, the larval survival rate increased with the density. The values of survival rate were respectively 30.53 ± 4.32 and 55.30 ± 21.70 % for the densities 1 ind./l and 20 ind./l.
1) The study examined growth rates in 5 species of lanternfish (family Myctophidae) larvae from the eastern Gulf of Mexico by measuring their length and weight over time.
2) Larval period length varied between species from 31 days for Ceratoscopelus townsendi to 60 days for Notolychnus valdiviae.
3) Growth rates in length also varied between species, ranging from 0.1 mm/day for N. valdiviae to 0.4 mm/day for C. townsendi.
Evolution of North American MicruracarusRachel Shoop
My research focuses on the evolution of North American water mites in the genus Arrenurus, Subgenus Micruracarus. In this presentation, I discuss why I chose to study these little known critters, and present some preliminary findings. Please contact me for more info.
The presentation of the CESAB group gaspar at the 2016 french ecology conference in the FRB-CESAB session "Using a treasury of knowledge to tackle complex ecological questions." Presenter: Michel Kulbicki
This document summarizes a study on the age, growth, and mortality of Tylochromis jentinki, an important fish species for fisheries in Ebrié Lagoon, Ivory Coast. Monthly samples of 1850 T. jentinki were collected between 2004-2006. Growth parameters were estimated using length frequency data analyzed with ELEFAN, including L∞=25 cm, K=0.67 yr-1, and t0=-0.28 yr-1. Total mortality (Z) was estimated at 2.38 yr-1, with fishing mortality (F) of 0.93 yr-1 and natural mortality (M) of 1.45 yr-1. The stock was considered
East Coast MARE Ocean Lecture Jan 30, 2013 - Corals: Changes with Climatecoseenow
East Coast MARE hosted an Ocean Lecture & Educators’ Night for K-12 teachers focused on bringing ocean literacy to students in New Jersey. Ms. Jeana Drake of Rutgers University presented the scientific lecture on Jan 30, 2013. For more information visit http://coseenow.net/mare/opportunities-resources/ocean-lecture-educators-night/.
Dynamics of extinction and survival in the Caribbean and the future of biodiv...Liliana Davalos
The document summarizes research on extinction dynamics in the Caribbean. It discusses how early equilibrium models of island biogeography have been challenged by disequilibrium dynamics seen in the Caribbean, including multiple waves of extinction. Several studies are highlighted that use fossil and genetic data to determine extinction timing for various bat and small mammal species. The arrival of humans in the Caribbean, through four migration waves, corresponded with many extinction events, though some pre-dated humans as well. A model is presented that aims to predict extinction risk factors at the species and island level, finding traits like body size as well as island characteristics influence survival. The talk concludes by discussing the importance of the findings for contemporary conservation efforts.
This document provides an overview of a central Florida freshwater turtle study being conducted at Wekiwa Springs State Park. The study aims to capture and collect data from multiple turtle species to estimate their population sizes. Researchers use marking and capture-recapture methods along with the Jolly-Seber model to calculate population point estimates and confidence intervals. Key turtle species discussed include snapping turtles, softshell turtles, chicken turtles, musk turtles, and cooters. Over 2,100 individual turtles representing seven species have been captured and measured since 1999.
This document is the first progress report of Amelia Lamb's research on the effects of shrubs and understory annual plants on kangaroo rat species in a desert annual community. The report summarizes previous literature on positive plant interactions and the stress gradient hypothesis. It also describes the study site and species, and outlines the methods for surveys to examine animal activity along a shrub and annual plant gradient, and foraging experiments using giving-up density trials to study kangaroo rat foraging patterns. Current objectives include further analyzing pilot study data, and carrying out extensive field surveys and experiments in April and May.
Three sentences:
Using telemetry data, researchers studied steelhead smolt survival through Puget Sound to identify causes of low survival. Telemetry tags on smolts from the Green and Nisqually Rivers showed lower survival for hatchery fish and those with longer migrations. Analysis of encounters between tagged smolts and seals fitted with receivers indicated that seals were a potential predator and some smolts stopped moving, suggesting predation had occurred.
Shark introduction Morphology and its behaviour characteristicsArubSultan
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha (or Selachii) and are the sister group to the Batoidea (rays and kin). Some sources extend the term "shark" as an informal category including extinct members of Chondrichthyes (cartilaginous fish) with a shark-like morphology, such as hybodonts. They generally do not live in freshwater, although there are a few known exceptions, such as the bull shark and the river shark, which can be found in both seawater and freshwater.Sharks have a covering of dermal denticles that protects their skin from damage and parasites in addition to improving their fluid dynamics. They have numerous sets of replaceable teeth.
Giant Australian cuttlefish: a globally unique species under threat. University of Adelaide
Associate Professor Bronwyn Gillanders presents the fourth installment of the Science Seminar Series entitled "Giant Australian cuttlefish: a globally unique species under threat."
This study investigated the potential costs of acclimatization to warmer temperatures in the reef coral Acropora millepora and its symbiotic algae. Field and laboratory experiments found that A. millepora colonies with thermally tolerant symbiont type D grew more slowly than those with sensitive type C2 under normal temperatures. Growth was severely reduced for over 18 months after a bleaching event for all colony types. The stresses of heat damage and symbiont changes may compound to significantly compromise the growth and resilience of reef-building corals.
The document summarizes a study monitoring the recovery of corals in Singapore that bleached during the 1998 global bleaching event. Surveys of coral reefs in June 1998 found 50-90% of corals were bleached. A monitoring program tagged 35 coral colonies over 10 surveys. Some corals recovered but others died. Recovery varied between genera. Chlorophyll levels increased over time. Sea surface temperatures in early 1998 were unusually high, likely causing the bleaching. Continued monitoring is needed to understand bleaching and aid coral reef recovery.
This study examined the dental health of muskox and caribou populations that have been declining in recent decades. Jaws were collected from hunted animals in 2015-2016 and examined for abnormalities. The results showed muskox had more dental issues than caribou, especially broken front incisors. When compared to data from 1990, the prevalence of broken incisors in muskox from Cambridge Bay had significantly increased from 30% to 100%. This suggests the dental health of these populations is deteriorating, with muskox being more severely affected, which could further impair their health and contribute to population declines.
Aspects of the biology of african moony, monodactylus sebae from badagry cree...Alexander Decker
The document summarizes a study on the biology of the African moony fish (Monodactylus sebae) in Badagry Creek, Lagos, Nigeria. A total of 267 fish were collected from May 2012 to April 2013. The fish lengths ranged from 56-163 mm and weights ranged from 5.6-151.7 g. The length-weight relationship showed negative allometric growth. The condition factor was higher in females than males. The sex ratio was approximately 1:1 male to female.
This document summarizes several studies on the public health impacts of surface disposal and smearing of human feces in alpine, forest, and arid environments. The studies found that:
1) Fecal bacteria can survive on snow but numbers decrease significantly within a week as the feces dry out. Deeper in feces, bacteria survive longer but decrease by one order of magnitude every 3-4 weeks.
2) Smeared feces on rocks in alpine, forest, and desert environments begin drying immediately and disappear almost completely within 8 weeks, with 84-95% weight loss on average.
3) Surrounding soils do not become significantly contaminated by bacteria washing from drying feces. This
Morphometric variation was found between sexes and among eight geographic areas for yellowtail flounder. Females had relatively deeper abdomens and larger heads than males. Samples from Newfoundland had relatively shorter bodies, deeper abdomens and longer heads than those from south of Nova Scotia. Morphometric analyses classified 71-95% of yellowtail to the correct Canadian area, but accuracy was lower for areas off the northeastern United States (43-76%). While shape differences were consistent with differences in growth rates among groups, the differences were not strong enough to clearly delineate stocks off the northeastern United States.
This document discusses the evolution of ground squirrels (Spermophilus) and controversies in their phylogenetic classification. It proposes using alarm calling behavior as a novel method for phylogenetic analysis, comparing alarm calling in Urocitellus ground squirrels and Marmots. While skull and DNA analyses have limitations, alarm calling reflects lifestyle and social behaviors that may help clarify evolutionary relationships within rodents.
1) The study examined growth rates in 5 species of lanternfish (family Myctophidae) larvae from the eastern Gulf of Mexico by measuring their length and weight over time.
2) Larval period length varied between species from 31 days for Ceratoscopelus townsendi to 60 days for Notolychnus valdiviae.
3) Growth rates in length also varied between species, ranging from 0.1 mm/day for N. valdiviae to 0.4 mm/day for C. townsendi.
Evolution of North American MicruracarusRachel Shoop
My research focuses on the evolution of North American water mites in the genus Arrenurus, Subgenus Micruracarus. In this presentation, I discuss why I chose to study these little known critters, and present some preliminary findings. Please contact me for more info.
The presentation of the CESAB group gaspar at the 2016 french ecology conference in the FRB-CESAB session "Using a treasury of knowledge to tackle complex ecological questions." Presenter: Michel Kulbicki
This document summarizes a study on the age, growth, and mortality of Tylochromis jentinki, an important fish species for fisheries in Ebrié Lagoon, Ivory Coast. Monthly samples of 1850 T. jentinki were collected between 2004-2006. Growth parameters were estimated using length frequency data analyzed with ELEFAN, including L∞=25 cm, K=0.67 yr-1, and t0=-0.28 yr-1. Total mortality (Z) was estimated at 2.38 yr-1, with fishing mortality (F) of 0.93 yr-1 and natural mortality (M) of 1.45 yr-1. The stock was considered
East Coast MARE Ocean Lecture Jan 30, 2013 - Corals: Changes with Climatecoseenow
East Coast MARE hosted an Ocean Lecture & Educators’ Night for K-12 teachers focused on bringing ocean literacy to students in New Jersey. Ms. Jeana Drake of Rutgers University presented the scientific lecture on Jan 30, 2013. For more information visit http://coseenow.net/mare/opportunities-resources/ocean-lecture-educators-night/.
Dynamics of extinction and survival in the Caribbean and the future of biodiv...Liliana Davalos
The document summarizes research on extinction dynamics in the Caribbean. It discusses how early equilibrium models of island biogeography have been challenged by disequilibrium dynamics seen in the Caribbean, including multiple waves of extinction. Several studies are highlighted that use fossil and genetic data to determine extinction timing for various bat and small mammal species. The arrival of humans in the Caribbean, through four migration waves, corresponded with many extinction events, though some pre-dated humans as well. A model is presented that aims to predict extinction risk factors at the species and island level, finding traits like body size as well as island characteristics influence survival. The talk concludes by discussing the importance of the findings for contemporary conservation efforts.
This document provides an overview of a central Florida freshwater turtle study being conducted at Wekiwa Springs State Park. The study aims to capture and collect data from multiple turtle species to estimate their population sizes. Researchers use marking and capture-recapture methods along with the Jolly-Seber model to calculate population point estimates and confidence intervals. Key turtle species discussed include snapping turtles, softshell turtles, chicken turtles, musk turtles, and cooters. Over 2,100 individual turtles representing seven species have been captured and measured since 1999.
This document is the first progress report of Amelia Lamb's research on the effects of shrubs and understory annual plants on kangaroo rat species in a desert annual community. The report summarizes previous literature on positive plant interactions and the stress gradient hypothesis. It also describes the study site and species, and outlines the methods for surveys to examine animal activity along a shrub and annual plant gradient, and foraging experiments using giving-up density trials to study kangaroo rat foraging patterns. Current objectives include further analyzing pilot study data, and carrying out extensive field surveys and experiments in April and May.
Three sentences:
Using telemetry data, researchers studied steelhead smolt survival through Puget Sound to identify causes of low survival. Telemetry tags on smolts from the Green and Nisqually Rivers showed lower survival for hatchery fish and those with longer migrations. Analysis of encounters between tagged smolts and seals fitted with receivers indicated that seals were a potential predator and some smolts stopped moving, suggesting predation had occurred.
Shark introduction Morphology and its behaviour characteristicsArubSultan
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha (or Selachii) and are the sister group to the Batoidea (rays and kin). Some sources extend the term "shark" as an informal category including extinct members of Chondrichthyes (cartilaginous fish) with a shark-like morphology, such as hybodonts. They generally do not live in freshwater, although there are a few known exceptions, such as the bull shark and the river shark, which can be found in both seawater and freshwater.Sharks have a covering of dermal denticles that protects their skin from damage and parasites in addition to improving their fluid dynamics. They have numerous sets of replaceable teeth.
Giant Australian cuttlefish: a globally unique species under threat. University of Adelaide
Associate Professor Bronwyn Gillanders presents the fourth installment of the Science Seminar Series entitled "Giant Australian cuttlefish: a globally unique species under threat."
This study investigated the potential costs of acclimatization to warmer temperatures in the reef coral Acropora millepora and its symbiotic algae. Field and laboratory experiments found that A. millepora colonies with thermally tolerant symbiont type D grew more slowly than those with sensitive type C2 under normal temperatures. Growth was severely reduced for over 18 months after a bleaching event for all colony types. The stresses of heat damage and symbiont changes may compound to significantly compromise the growth and resilience of reef-building corals.
The document summarizes a study monitoring the recovery of corals in Singapore that bleached during the 1998 global bleaching event. Surveys of coral reefs in June 1998 found 50-90% of corals were bleached. A monitoring program tagged 35 coral colonies over 10 surveys. Some corals recovered but others died. Recovery varied between genera. Chlorophyll levels increased over time. Sea surface temperatures in early 1998 were unusually high, likely causing the bleaching. Continued monitoring is needed to understand bleaching and aid coral reef recovery.
This study examined the dental health of muskox and caribou populations that have been declining in recent decades. Jaws were collected from hunted animals in 2015-2016 and examined for abnormalities. The results showed muskox had more dental issues than caribou, especially broken front incisors. When compared to data from 1990, the prevalence of broken incisors in muskox from Cambridge Bay had significantly increased from 30% to 100%. This suggests the dental health of these populations is deteriorating, with muskox being more severely affected, which could further impair their health and contribute to population declines.
Aspects of the biology of african moony, monodactylus sebae from badagry cree...Alexander Decker
The document summarizes a study on the biology of the African moony fish (Monodactylus sebae) in Badagry Creek, Lagos, Nigeria. A total of 267 fish were collected from May 2012 to April 2013. The fish lengths ranged from 56-163 mm and weights ranged from 5.6-151.7 g. The length-weight relationship showed negative allometric growth. The condition factor was higher in females than males. The sex ratio was approximately 1:1 male to female.
This document summarizes several studies on the public health impacts of surface disposal and smearing of human feces in alpine, forest, and arid environments. The studies found that:
1) Fecal bacteria can survive on snow but numbers decrease significantly within a week as the feces dry out. Deeper in feces, bacteria survive longer but decrease by one order of magnitude every 3-4 weeks.
2) Smeared feces on rocks in alpine, forest, and desert environments begin drying immediately and disappear almost completely within 8 weeks, with 84-95% weight loss on average.
3) Surrounding soils do not become significantly contaminated by bacteria washing from drying feces. This
Morphometric variation was found between sexes and among eight geographic areas for yellowtail flounder. Females had relatively deeper abdomens and larger heads than males. Samples from Newfoundland had relatively shorter bodies, deeper abdomens and longer heads than those from south of Nova Scotia. Morphometric analyses classified 71-95% of yellowtail to the correct Canadian area, but accuracy was lower for areas off the northeastern United States (43-76%). While shape differences were consistent with differences in growth rates among groups, the differences were not strong enough to clearly delineate stocks off the northeastern United States.
This document discusses the evolution of ground squirrels (Spermophilus) and controversies in their phylogenetic classification. It proposes using alarm calling behavior as a novel method for phylogenetic analysis, comparing alarm calling in Urocitellus ground squirrels and Marmots. While skull and DNA analyses have limitations, alarm calling reflects lifestyle and social behaviors that may help clarify evolutionary relationships within rodents.
2. • Xenopus occur throughout sub-Saharan Africa
(Kobel et al., 1981 Picker & De Villiers, 1989; Minter et al., 2004)
• 2 species present in south-western Cape (Kobel et al.,
1981 Picker & De Villiers, 1989; Minter et al., 2004)
3. • During the winter rains X. laevis move into the
habitat of X. gilli
• X. laevis poses a threat to X. gilli
– Predation
– Competition
– Hybridization
No conservation
for X. gilli
X. gilli conserved
since 1985
4. • More on the Ecology of Xenopus
• To test the fully aquatic status of Xenopus
• To determine the movement capabilities and
population structure of these two Xenopus
species
• To determine if these two species differ in
these aspects
Aquatic
TerrestrialAquatic
6. Chap 1 Intro
• Dispersal present in most organisms (Clobert et
al., 2009)
–Not static but differs between and within
species (Altwegg et al., 2000; Schneider et al., 2003; Mennechez et al., 2004;
Bowler & Benton, 2009; Clobert et al., 2009; Stevens et al., 2010)
–Certain cost involved in dispersal (Bowler & Benton,
2005; Clobert et al., 2009)
7. Dispersal ability
or observed
performance
Lab based
performance
or maximal
performance
Morphology
Chap 1 Intro
Ref: Stevens et al., 2010; Garland & Losos, 1994;
Zug, 1972; Arnold & Bennett, 1984
http://images.natureworldnews.com/data/images/full/2450/cane-toad-in-australia.jpg
Increased Dispersal
Alford et al., 2009
Increased Endurance
Llewelyn et al., 2010
Longer leg length
Phillips et al., 2006
8. • Amphibians classified as poor dispersers
(Avise, 2000)
–Smith & Green (2005) shown that 44% of
anurans disperse > 1km
–Study only report on single maximum
events
–Study also lacks aquatic anurans
Chap 1 Intro
9. • Xenopus highly adapted for aquatic
lifestyle(Trueb, 1996)
–Irrigation readily used for dispersal (Tinsley et al., 1996; Lobos
& Measey, 2002; Measey, 2004)
–Overland dispersal documented (see Kalk, 1960; Passmore &
Carrunthers, 1979; Picker, 1985; Schramm, 1987; De Bruyn et al., 1996; Measey & Tinsley, 1998; Fouquet & Measey, 2006; Faraone et
al., 2008)
Chap 1 Intro
10. Aim:
1. Determine the dispersal ability and the
relative performance
2. Compare dispersal ability and relative
performance
H1: Xenopus laevis will outperform X. gilli
in both dispersal and relative
performance
Chap 1 Intro
11. • Frogs captured through trapping and seining
• Frogs tagged using PIT tags:
– X. gilli tagged at both sites
– X. laevis tagged only in Kleinmond
Chap 1 Intro M & M
12. • 20 (10 males & 10 females) X. gilli & X. laevis
collected
• All performance trials done
at 20˚C
• Dry & wet endurance
determined on 4m circular track
• Jumping & swimming speed were determined by
filming the animals at 240fps
• Performance compared using an ANCOVA
Chap 1 Intro M & M
13. • Literature search to determine which
morphological characters associated with
performance traits
• Log transformed stepwise regression was
done in support of literature
• GLM was used to fit different morphological
characters
• Best model based on Δ AIC
Chap 1 Intro M & M
14. • Tagged frogs were released in their origin
ponds
• Euclidean distances measured from
origin pond to destination pond
• Distances compared using a MANOVA in
R (R Development Core Team, 2015)
Chap 1 Intro M & M
16. CoGH X. gilli Kleinmond X. gilli X. laevis
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Swimspeedm.s-1
*
*
CoGH X. gilli Kleinmond X. gilli X. laevis
4.0
4.2
4.4
4.6
4.8
5.0
5.2
Log(Wetendurancedistance(mm))
* *
Chap 1 Intro M & M R & D
17. • Jumping performance related to leg
morphology
– Gomes et al. (2009) & Tejedo et al. (2000) showed
jump distance related to leg length
– Herrel et al. (2012) & Llewelyn et al. (2010)
showed endurance is related to leg length
Chap 1 Intro M & M R & D
18. • Swimming speed related to Illium length and
width in X. gilli
– Supported by Videler and Jorna (1985)
• Swimming endurance related to leg length in
X. gilli
• X. laevis with the longest tibia swam the
fastest but the frogs with the longest bodies
swam the furthest
Chap 1 Intro M & M R & D
19. Chap 1 Intro M & M R & D
CoGH X. gilli Kleinmond X. gilli X. laevis
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
Log(distance(m))
90 (5.17%)6 (1.01%)46 (4.01%)
20. Chap 1 Intro M & M R & D
200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600
0
10
20
30
40
50
200 400 600 800 1000 1200 1400 1600 1800
0
10
20
30
40
50
Frequency
Distance (m)
1560m within 3 weeks
21. Ch 1 Intro M & M R & D
0
5
10
15
20
25
30
35
40
Feb
'14
Mar
'14
Apr
'14
May
'14
Jun
'14
Jul
'14
Aug
'14
Sep
'14
Oct
'14
Nov
'14
Dec
'14
Jan
'15
Feb
'15
Mar
'15
Apr
'15
May
'15
Jun
'15
Jul
'15
Aug
'15
Sep
'15
Oct
'15
Frequency
23. • Population structure important method to
monitor amphibian populations (Leberton et al., 1992;
Schmidt, 2003)
– Important for assessment of IUCN status (see IUCN,
2012)
– No data on population structure of SA frogs (see
Measey, 2011; IUCN 2012)
Chap 1 Intro M & M R & D Chap 2 Intro
24. Frequency
Age
Chap 1 Intro M & M R & D Chap 2 Intro
Age
Frequency
NumberofSurvivors
Age
Survival
Survival
Age
25. • X. laevis has a suggested negative effect
X. gilli
• CoGH and Kleinmond different
conservation histories
– Opportunity to determine if X. laevis has a
negative affect on X. gilli
Chap 1 Intro M & M R & D Chap 2 Intro
26. Aim
1. Obtain information on the age
structure, growth and survival
2. Determine whether X. laevis has a
negative effect on X. gilli
H1: The presence of Xenopus laevis has a
negative effect on the survival as well as
the age structure of Xenopus gilli
Chap 1 Intro M & M R & D Chap 2 Intro
27. • Outer toe from 40 frogs (20 males & 20 Females)
of each species from each site
• Each toe was sectioned
and stained using
standard
skeletochronological
techniques
• The relationship between
number of LAG and SVL
was determined using
non-linear regression
(R Core team, 2015)
Chap 1 Intro M & M R & D Chap 2 Intro M & M
28. • All frogs that were captured were sexed and
photographed
– If a frog was recapture it was photographed again
• The difference in SVL was determined and
growth expressed as Growth/day
• Relationship between growth and initial SVL
was expressed by a non-linear regression (R Core
team, 2015)
Chap 1 Intro M & M R & D Chap 2 Intro M & M ImageJ
29. • Frogs were captured on 3 consecutive days
every 3 to 6 weeks
– Recapture events were recorded in binary (1 & 0)
• CJS model was used to determine the survival
of the frogs
Chap 1 Intro M & M R & D Chap 2 Intro M & M
20 30 40 50 60 70 80 90 100 110 120 130 140
0
100
200
300
400
500
600
20 25 30 35 40 45 50 55 60 65 70 75
0
100
200
300
400
500
600
Small Large Small Large
31. Chap 1 Intro M & M R & D Chap 2 Intro M & M R & D
-0.02 -0.01 0.00 0.01 0.02 0.03 0.04
30
35
40
45
50
55
60
65
70
75
-0.04 -0.02 0.00 0.02 0.04 0.06 0.08 0.10 0.12
30
35
40
45
50
55
60
65
70
-0.12 -0.08 -0.04 0.00 0.04 0.08 0.12 0.16
30
40
50
60
70
80
90
100
110
120
130
SVL
Growth/day
32. Chap 1 Intro M & M R & D Chap 2 Intro M & M R & D
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Summer '14 Winter'14 Summer '14/'15 Winter '15 Summer '15
Survival
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Summer '14 Winter'14 Summer '14/'15 Winter '15 Summer '15
Survival
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Summer '14 Winter'14 Summer '14/'15 Winter '15 Summer '15
Survival
X. laevis: 0.381
Kleinmond: 0.316
CoGH: 0.562
33. • Xenopus are principally aquatic rather than
fully aqautic
• X. laevis better jumper and swimmer
• X. laevis higher dispersal frequency
• Skeletochronology not effective in age
determination of Cape Xenopus
• Survival is reduced in Kleinmond X. gilli
34. • Kleinmond
– Origin of X. laevis in temp ponds
– Aestivation place of X. gilli
• CoGH
– Breeding sites of X. gilli
– Fate of X. gilli after the ponds dry up