Effects of prey size and mobility on prey-capture kinematics in leopard sharks triakis semifasciata

1998 ◽  
Vol 201 (16) ◽  
pp. 2433-2444 ◽  
Author(s):  
LA Ferry-Graham
Keyword(s):  
Prey Item ◽  
High Speed ◽  
Prey Capture ◽  
Live Prey ◽  
Leopard Shark ◽  
Suction Index ◽  
Item Size ◽  
Triakis Semifasciata ◽  
Leopard Sharks ◽  
Prey Items

Recent work on teleosts suggests that attack behaviors or kinematics may be modified by a predator on the basis of the size of the prey or the ability of the prey to sense predators and escape capture (elusivity). Sharks are generally presumed to be highly visual predators; thus, it is reasonable to expect that they might also be capable of such behavioral modulation. In this study, I investigated the effect of prey item size and type on prey-capture behavior in leopard sharks (Triakis semifasciata) that had been acclimated to feeding in the laboratory. Using high-speed video, sharks were filmed feeding on two sizes of the same prey item (thawed shrimp pieces) and two potentially more elusive prey items (live earthworms and live mud shrimp). In leopard sharks, little effect of prey elusivity was found for kinematic variables during prey capture. However, the large proportion of successful captures of the live prey suggests that they did not prove to be truly elusive prey items for the leopard shark. There were significant size effects on prey-capture kinematics, with the larger non-elusive items inducing greater head expansion during prey capture. Ram-suction index values also indicated that strikes on large, non-elusive prey had a significantly larger suction component than strikes on similar small prey items. This finding is interesting given that the two sizes of non-elusive prey item offered no differential challenge in terms of a performance consequence (reduced capture success).

Feeding kinematics of juvenile swellsharks, Cephaloscyllium ventriosum

1997 ◽  
Vol 200 (8) ◽  
pp. 1255-1269 ◽  
Author(s):  
L Ferry-Graham
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Buccal Cavity ◽  
Video Recording ◽  
Large Prey ◽  
Feeding Behaviors ◽  
Suction Index ◽  
Item Size ◽  
Prey Items ◽  
Cephaloscyllium Ventriosum

To investigate how feeding behaviors change with prey size, high-speed video recording was used to examine the kinematics of prey capture and transport in 1-year-old swellsharks Cephaloscyllium ventriosum (Scyliorhinidae: Carchariniformes) feeding on two differently sized prey items. Prey capture in these sharks generally consisted of an initially ram-dominated capture bite, one or more manipulation bites, a holding phase during which the food was held in the teeth of the shark, and then suction-dominated prey transport. During initial capture and transport, most of the water taken in is forced back out of the mouth anteriorly rather than continuing posteriorly out through the gill openings. Dye experiments in which dye-perfused prey items were ingested by the sharks confirm this observation; distinct jets of colored water were video-taped as they were ejected from the mouth. Very late in prey transport, a bolus of water is ejected through the gill slits; however, by this time, the majority of water appears already to have exited the buccal cavity through the mouth. Such patterns were observed for sharks feeding on both small and large prey items. Although a basic pattern of prey capture and transport was regularly repeated among strikes, kinematic patterns during prey capture and transport were variable both within and among individuals, indicating that prey acquisition is not tightly controlled. However, the amount of variability was similar among prey sizes. In addition, there were no detectable changes in behavior due to prey item size. Ram-suction index values confirmed that similar capture modes were being utilized for both prey sizes.

scholarly journals Heterocercal tail function in leopard sharks: a three-dimensional kinematic analysis of two models

1996 ◽  
Vol 199 (10) ◽  
pp. 2253-2268 ◽  
Author(s):  
L Ferry ◽  
G Lauder
Keyword(s):  
High Speed ◽  
Classical Model ◽  
Three Dimensional ◽  
Strong Support ◽  
Three Dimensions ◽  
Video Cameras ◽  
Leopard Shark ◽  
Triakis Semifasciata ◽  
Leopard Sharks ◽  
Tail Function

Two different models have been proposed to explain the function of the heterocercal tail in shark locomotion. The classical model proposes that, as a result of lift generated by the tail as it beats, the net force acting on the tail is directed dorsally and anteriorly. In contrast, Thomson's model suggests that the tail generates a net force directed through the shark's center of gravity, i.e. ventrally and anteriorly. In this study, we evaluate these two models by describing the three-dimensional kinematics of the heterocercal tail in the leopard shark Triakis semifasciata during swimming. Lateral and posterior views of the tail were examined from four individuals swimming in a flow tank at 1.2 L s-1 (where L is total length) using two high-speed video cameras filming simultaneously at 250 fields s-1. These two simultaneous views allowed eight landmarks on the tail to be followed in three dimensions through time. These landmarks allowed the tail to be divided into separate surfaces whose orientation over time was calculated. Points located anteriorly on the tail go through significantly smaller excursions and reach their maximum lateral excursion significantly earlier in the beat cycle than points on the trailing edge of the tail. Three-dimensional angle calculations show that the terminal lobe leads the ventral lobe through a beat, as predicted by the classical model. Dye-stream visualizations confirmed that this pattern of movement deflects water ventrally and posteriorly to the moving tail, providing strong support for the classical model. Additionally, our results show that a three-dimensional analysis is critical to understanding the function of the heterocercal tail.

Demography of the central california population of the Leopard Shark (Triakis semifasciata)

1992 ◽  
Vol 43 (1) ◽  
pp. 183 ◽  
Author(s):  
GM Cailliet
Keyword(s):  
Population Growth ◽  
Reproductive Rate ◽  
Shark Species ◽  
Sandbar Shark ◽  
Lemon Shark ◽  
Carcharhinus Plumbeus ◽  
Net Reproductive Rate ◽  
Leopard Shark ◽  
Triakis Semifasciata ◽  
Leopard Sharks

Demographic analyses can be quite useful for effectively managing elasmobranch fisheries. However, they require valid estimates of age-specific mortality and natality rates, in addition to information on the distribution, abundance, habits and reproduction of the population, to produce reliable estimates of population growth. Because such detailed ecological information is usually unavailable, complete demographic analyses have been completed for only four shark species: the spiny dogfish, Squalus acanthias; the soupfin shark, Galeorhinus australis; the lemon shark, Negaprion brevirostris; and most recently the sandbar shark, Carcharhinus plumbeus. In California, reliable estimates of age, growth, mortality, age at maturity, and fecundity are available only for the leopard shark, Triakis semifasciata. A demographic analysis of this species yielded a net reproductive rate (Ro) of 4.467, a generation time (G) of 22.35 years, and an estimate of the instantaneous population growth coefficient (r) of 0.067. If the mean fishing pressure over 10 years (F= 0.084) is included in the survivorship function, Ro and r are reduced considerably, especially if leopard sharks first enter the fishery at early ages. A size limit of 120 cm TL (estimated age 13 years), especially for female sharks, is tentatively proposed for the leopard shark fishery.

Quantitative analysis of prey-capture kinematics in Anolis equestris (Reptilia: Iguanidae)

1990 ◽  
Vol 68 (10) ◽  
pp. 2192-2198 ◽  
Author(s):  
Vincent L. Bels
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Anterior Part ◽  
The Body ◽  
Original Position ◽  
Forward Movement ◽  
Live Prey ◽  
Capture Process ◽  
Locomotor System ◽  
Cyclic Movement

High-speed cinematography was employed to study the mechanics of prey capture in Anolis equestris. Capture of live prey (adult locusts) consists of a cyclic movement of the upper and lower jaws combined with tongue protraction. Kinematic profiles are presented for the jaws, tongue, and forelimbs. The tongue is projected during the "slow open" stage and most of the "fast open" stage. The tongue protrudes beyond the mandibular symphysis during the slow open stage, and rotates simultaneously around a transverse anteromedian axis. The prey is thus contacted by the dorsal sticky surface of the tongue, and then pulled backward into the oral cavity by a combination of a forward movement of the jaws and retraction of the tongue. Gape angle, defined as the angle between the upper and lower jaws, continues to increase during the initial stages of tongue retraction. During the capture process, the anterior part of the body lunges forward, followed by a return to its original position; this displacement is mediated by the forelimbs, which usually remain well anchored to the floor. The cyclic food-capture movements of the jaws and tongue–hyoid system in A. equestris (Iguanidae) and Chameleo dilepis (Chamaeleontidae) are compared. I argue that one of the primary selection forces in the evolution of the different mechanisms of prey prehension in these two lizard groups was enhancement of the locomotor system and, consequently, foraging ability.

Do flatfish feed like other fishes? A comparative study of percomorph prey-capture kinematics.

1997 ◽  
Vol 200 (22) ◽  
pp. 2841-2859 ◽  
Author(s):  
A Gibb
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Multivariate Analyses ◽  
Lepomis Macrochirus ◽  
Experimental Methodology ◽  
Flatfish Species ◽  
Significant Difference ◽  
Jaw Protrusion ◽  
Suction Index ◽  
Post Hoc

The kinematics of prey capture in two bilaterally asymmetrical pleuronectiform flatfish species (Pleuronichthys verticalis and Xystreurys liolepis) and two symmetrical percomorph species (Lepomis macrochirus, a centrarchid, and Cheilinus digrammus, a labrid) were compared to test the hypothesis that flatfish have distinct prey-capture kinematics from those quantified for other percomorph fishes. Size-matched individuals of both flatfish species were video-taped feeding using a high-speed video system. Cephalic displacement and timing variables were quantified and compared with data from similarly sized L. macrochirus and C. digrammus previously collected by other researchers using similar experimental methodology. Nested multivariate analyses of variance indicated that there was no significant difference in prey-capture kinematics between flatfish and non-flatfish taxa, but that prey-capture kinematics did differ among the four taxa. Multiple nested analyses of variance revealed that the taxa differed in 7 of 11 kinematic variables. Post-hoc tests and comparisons with other fish taxa suggest that individuals of P. verticalis possess an unusual combination of prey-capture kinematics including large hyoid depression, large neurocranial rotation, large upper jaw protrusion and small gape. Previous research has suggested that this combination of traits is associated with suction-based prey capture. Correspondingly, the ram­suction index calculated for P. verticalis is more negative (indicating a greater use of suction) than that calculated for the other taxa. When homologous kinematic variables are compared across these four taxa, flatfish do not appear to have similar prey-capture kinematics. However, both flatfish species are distinct from the two symmetrical percomorph species in their asymmetrical jaw movements.

scholarly journals Ontogeny of feeding morphology and kinematics in juvenile fishes: a case study of the cottid fish Clinocottus analis

1996 ◽  
Vol 199 (9) ◽  
pp. 1961-1971
Author(s):  
A Cook
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Least Squares Regression ◽  
Suction Feeding ◽  
Juvenile Period ◽  
Feeding Mode ◽  
Feeding Morphology ◽  
Suction Index ◽  
And Behavior

The development of feeding morphology, kinematics and behavior was examined in the juveniles of the cottid fish Clinocottus analis. The attacks of 18 juvenile C. analis, between 17.59 mm and 42.15 mm in standard length (SL), feeding on brown worms were filmed using high-speed video. Feeding mode, ram- or suction-dominated, kinematic variables and morphology were quantified and compared over the juvenile period. The analysis of these three factors was based on the following questions: (1) do they change over ontogeny; (2) how do their values compare with those of larvae, juveniles and adults of other species; and (3) what is the level of stereotypy, as measured by the variance in these factors, at this stage in ontogeny and does it change? Small C. analis juveniles have the small gape and large buccal cavity of a suction feeder, and this morphology becomes more pronounced as they become larger. The kinematic variables of C. analis juveniles are similar to those of adult suction-feeding cottids and least-squares regression analysis showed significant changes in only two variables (time to prey capture and absolute attack predator­prey distance) over the juvenile period. Feeding mode, as measured by the ram-suction index, shows an increase in the suction component of the strike with increasing size. This study demonstrates that, in C. analis, suction feeding behavior develops during the juvenile period. Within the juvenile stage, morphology, prey-capture kinematics and feeding mode are not tightly linked ontogenetically such that suction-feeder kinematics (short predator­prey distance and low attack velocity) and basic morphology (small gape, large buccal volume) develop much earlier than the employment of a large suction component during the strike.

scholarly journals The Epidermal Microbiome Within An Aggregation of Leopard Sharks (Triakis Semifasciata) Has Taxonomic Flexibility With Gene Functional Stability Across Three Time-Points

2021 ◽  
Author(s):  
Michael Doane ◽  
Colton Johnson ◽  
Shaili Johri ◽  
Emma N. Kerr ◽  
Megan M. Morris ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Functional Characterization ◽  
Time Points ◽  
Leopard Shark ◽  
Average Similarity ◽  
Microbial Groups ◽  
Triakis Semifasciata ◽  
Leopard Sharks ◽  
Biofilm Development ◽  
Host Metabolism

Abstract Background: The epidermis of Chondrichthyan fishes consists of dermal denticles with production of minimal but protein rich mucus that influence the attachment and biofilm development of microbes, facilitating a unique epidermal microbiome. Here, we use metagenomics to provide the taxonomic and functional characterization of the epidermal microbiome of the Triakis semifasciata (leopard shark) across three time-points to identify links between microbial groups and host metabolism. Our aims include 1) describing the variation of microbiome taxa over time and identify those members which are recurrent (present across all time-points, 2) investigating the relationship between the recurrent and flexible taxa (those which are not found consistently across time-points, 3) describing the functional compositions of the microbiome which may suggest links with the host metabolism; and 4) identifying whether the metabolisms are share across microbial genera or found in specific taxa. Results: Microbial members of the microbiome showed high similarity between all individuals (average similarity: 82.74) with relative abundance of those members varying across years, suggesting flexibility of taxa in the microbiome. One hundred and eighty-eight genera were identified as recurrent, including Pseudomonas, Erythrobacter, Alcanivorax, Marinobacter and Sphingopxis being consistently abundance across time-points, while Limnobacter and Xyella exhibited switching patterns with high relative abundance in 2013, Sphingobium and Sphingomona in 2015, and Altermonas, Leeuwenhoekiella, Gramella and Maribacter in 2017. Of the 188 genera identified as recurrent, the top 19 relative abundant genera forming three recurrent groups. The microbiome also displayed high functional similarity between individuals (average similarity: 97.65) with gene function composition being consistent across time-points. Conclusion: These results show that while presence of microbial genera exhibit consistency across time-points, their abundances do fluctuate. Functions however remain stable across time points; thus, we suggest the leopard shark microbiomes exhibit functional redundancy. We hypothesize this may be the result of the host’s epidermal attributes structuring the microbiome. In addition, we show the co-existence of many microbial genera that carry genes which may enable the microbes to use the nutrients provided by the elasmobranch’s metabolism.

scholarly journals Relative importance of growth and behaviour to elasmobranch suction-feeding performance over early ontogeny

2007 ◽  
Vol 5 (23) ◽  
pp. 641-652 ◽  
Author(s):  
Dayv Lowry ◽  
Philip J Motta
Keyword(s):  
Prey Capture ◽  
Volume Growth ◽  
Early Ontogeny ◽  
Maximum Pressure ◽  
Suction Feeding ◽  
Size Dependent ◽  
Chiloscyllium Plagiosum ◽  
Dietary Shifts ◽  
Triakis Semifasciata ◽  
Leopard Sharks

Development of the ability to capture prey is crucial to predator survival. Trends in food-capture performance over early ontogeny were quantified for leopard sharks Triakis semifasciata and whitespotted bamboosharks Chiloscyllium plagiosum by measuring suction pressure and flow in front of the mouth during feeding. At any size, C. plagiosum produce greater subambient pressure and ingest more rounded water parcels. Maximum subambient pressure scaled with negative allometry in T. semifasciata and was accompanied by an increase in the time to reach maximum gape. Despite a similar trend in buccal expansion timing, maximum pressure in C. plagiosum scaled with isometry and was accompanied by an earlier onset of hyoid depression and a positive allometric increase in buccal reserve volume. Growth was the primary factor responsible for developmental trends in both species, with size-independent behavioural changes contributing little to overall performance variability. Ontogenetic dietary shifts are predicted for both species as a consequence of size-dependent changes in performance. Chiloscyllium plagiosum becomes anatomically and behaviourally canalized towards suction feeding, limiting the effective range of prey capture and possibly necessitating stalking. Triakis semifasciata , by contrast, retains the flexibility to employ both ram and suction and therefore captures more elusive prey with age.

The mechanics of prey prehension in chameleons

2000 ◽  
Vol 203 (21) ◽  
pp. 3255-3263 ◽  
Author(s):  
A. Herrel ◽  
J.J. Meyers ◽  
P. Aerts ◽  
K.C. Nishikawa
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Prey Size ◽  
Nerve Transection ◽  
Surface Phenomena ◽  
High Speed Video ◽  
Video Recordings ◽  
Tongue Muscles ◽  
Stimulation Experiments ◽  
Prey Items

Iguanian lizards generally use their tongue to capture prey. Because lingual prehension is based on surface phenomena (wet adhesion, interlocking), the maximal prey size that can be captured is small. However, published records show that prey items eaten by chameleons include small vertebrates such as lizards and birds, indicating that these lizards are using a different prey prehension mechanism. Using high-speed video recordings, cineradiography, electromyography, nerve transection and stimulation experiments, we investigated the function of the tongue during prey capture. The results of these experiments indicate that chameleons have modified the primitive iguanian system by including a suction component in their prehension mechanism. Suction is generated by the activity of two modified intrinsic tongue muscles that pull the tongue pad inwards. Moreover, we demonstrate that the mechanism described here is a prerequisite for successful feeding.

scholarly journals The Epidermal Microbiome Within An Aggregation of Leopard Sharks (Triakis Semifasciata) Has Taxonomic Flexibility With Gene Functional Stability Across Three Time-Points

2021 ◽  
Author(s):  
Michael Doane ◽  
Colton Johnson ◽  
Shaili Johri ◽  
Emma N. Kerr ◽  
Megan M. Morris ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Functional Characterization ◽  
Time Points ◽  
Leopard Shark ◽  
Average Similarity ◽  
Microbial Groups ◽  
Triakis Semifasciata ◽  
Leopard Sharks ◽  
Biofilm Development ◽  
Host Metabolism

Abstract Background: The epidermis of Chondrichthyan fishes consists of dermal denticles with production of minimal but protein rich mucus that influence the attachment and biofilm development of microbes, facilitating a unique epidermal microbiome. Here, we use metagenomics to provide the taxonomic and functional characterization of the epidermal microbiome of the Triakis semifasciata (leopard shark) across three time-points to identify links between microbial groups and host metabolism. Our aims include 1) describing the variation of microbiome taxa over time and identify those members which are recurrent (present across all time-points, 2) investigating the relationship between the recurrent and flexible taxa (those which are not found consistently across time-points, 3) describing the functional compositions of the microbiome which may suggest links with the host metabolism; and 4) identifying whether the metabolisms are share across microbial genera or found in specific taxa. Results: Microbial members of the microbiome showed high similarity between all individuals (average similarity: 82.74) with relative abundance of those members varying across years, suggesting flexibility of taxa in the microbiome. One hundred and eighty-eight genera were identified as recurrent, including Pseudomonas, Erythrobacter, Alcanivorax, Marinobacter and Sphingopxis being consistently abundance across time-points, while Limnobacter and Xyella exhibited switching patterns with high relative abundance in 2013, Sphingobium and Sphingomona in 2015, and Altermonas, Leeuwenhoekiella, Gramella and Maribacter in 2017. Of the 188 genera identified as recurrent, the top 19 relative abundant genera forming three recurrent groups. The microbiome also displayed high functional similarity between individuals (average similarity: 97.65) with gene function composition being consistent across time-points. Conclusion: These results show that while presence of microbial genera exhibit consistency across time-points, their abundances do fluctuate. Functions however remain stable across time points; thus, we suggest the leopard shark microbiomes exhibit functional redundancy. We hypothesize this may be the result of the host’s epidermal attributes structuring the microbiome. In addition, we show the co-existence of many microbial genera that carry genes which may enable the microbes to use the nutrients provided by the elasmobranch’s metabolism.

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