scholarly journals First gut contents in a Cretaceous sea turtle

2005 ◽  
Vol 2 (1) ◽  
pp. 113-115 ◽  
Author(s):  
Benjamin P Kear
Keyword(s):  
Direct Evidence ◽  
Feeding Habits ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Benthic Invertebrate ◽  
The Body ◽  
Gut Contents ◽  
Feeding Strategies ◽  
Shell Fragments ◽  
Correct Size

Modern sea turtles utilize a variety of feeding strategies ranging from herbivory to omnivory. In contrast, the diets of fossil sea turtles are poorly known. This study reports the first direct evidence: inoceramid bivalve shell pieces (encased in phosphatic material) preserved within the body cavities of several small protostegid turtles (cf. Notochelone ) from the Lower Cretaceous of Australia. The shell fragments are densely packed and approximately 5–20 mm across. Identical shell accumulations have been found within coprolite masses from the same deposits; these are of a correct size to have originated from Notochelone , and indicate that benthic molluscs were regular food items. The thin, flexible inoceramid shells (composed of organic material integrated into a prismatic calcite framework) appear to have been bitten into segments and ingested, presumably in conjunction with visceral/mantle tissues and encrusting organisms. Although protostegids have been elsewhere interpreted as potential molluscivores, their primitive limb morphology is thought to have limited them to surface feeding. However, the evidence here that at least some forms were able to utilize benthic invertebrate prey indicates that, like modern sea turtles, protostegids probably exhibited a much broader range of feeding habits.

scholarly journals Can mandible morphology help predict feeding habits in Antarctic amphipods?

2020 ◽  
Vol 32 (6) ◽  
pp. 496-507
Author(s):  
Loïc N. Michel ◽  
Fabienne L. Nyssen ◽  
Patrick Dauby ◽  
Marie Verheye
Keyword(s):  
Functional Groups ◽  
Trophic Ecology ◽  
Feeding Habits ◽  
Gut Contents ◽  
Ecological Niches ◽  
Feeding Strategies ◽  
Generalist Predators ◽  
Dietary Specialization ◽  
Important Place ◽  
Antarctic Amphipod

AbstractIn Antarctica, amphipods form a highly diverse group, occupy many different ecological niches and hold an important place in food webs. Here, we aimed to test whether differences in Antarctic amphipod feeding habits were reflected in their mandible morphology, and if mouthpart specialization could be used to describe amphipod trophic ecology. To do so, we compared mandible morphology in nine species spanning seven families and five functional groups (grazers, suspension feeders, generalist predators, specialist predators and scavengers). Mandible morphology adequately depicted some aspects of amphipod trophic ecology, such as the trophic level at which animals feed or their degree of dietary specialization. On the other hand, links between mandible morphology and amphipod diet were seldom unambiguous or straightforward. Similar adaptations were found in distinct functional groups. Conversely, mandible morphology could vary within a single functional group, and phylogenetic effects sometimes complicated the interpretation of form-function relationships. Overall, mandible morphology on its own was generally not sufficient to precisely predict amphipod feeding strategies. However, when combined with other methods (e.g. gut contents, trophic markers), it constitutes a valuable source of information for integrative studies of amphipod ecological diversity in the Southern Ocean.

scholarly journals First report of the scavenging isopod Natatolana neglecta (Crustacea: Isopoda: Cirolanidae) feeding on a sea turtle

2019 ◽  
Vol 20 (2) ◽  
pp. 297
Author(s):  
OHIANA REVUELTA ◽  
FRANCESC DOMÈNECH ◽  
STEPHEN KEABLE ◽  
RAÚL MÍGUEZ-LOZANO
Keyword(s):  
Sea Turtles ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Dead Sea ◽  
Mediterranean Coast ◽  
Gut Contents ◽  
Post Mortem ◽  
Juvenile Male ◽  
Coelomic Cavity ◽  
Loggerhead Sea Turtle

A juvenile male loggerhead sea turtle (Caretta caretta) was found dead in April 2015, entangled in a trammel net on the Mediterranean coast of Spain. Post-mortem examination revealed the presence of ninety-five isopods dispersed in the coelomic cavity, and inside the oesophagus and skull. All individuals found scavenging on the sea turtle were identified as Natatolana neglecta (Hansen, 1890) (Isopoda: Cirolanidae). Genetic analysis of the isopod gut contents showed that they were feeding on turtle tissue, confirming that N. neglecta can also attack dead sea turtles. This study shows the value of cirolanids as potential indicators of the cause of death in stranded sea turtles.

Smaller longer, larger shorter: energy budget calculations explain intrapopulation variation in remigration intervals for loggerhead sea turtles (Caretta caretta)

2008 ◽  
Vol 86 (7) ◽  
pp. 595-600 ◽  
Author(s):  
Hideo Hatase ◽  
Katsumi Tsukamoto
Keyword(s):  
Feeding Habits ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Energy Budgets ◽  
Loggerhead Sea Turtles ◽  
Intrapopulation Variation ◽  
Turtle Population ◽  
The Difference ◽  
And Migration

Adult female loggerhead sea turtles ( Caretta caretta (L., 1758)) show a size-related behavioural and trophic dichotomy within several populations: oceanic planktivory by small females and neritic benthivory by large females. Within a Japanese population, smaller females have longer remigration intervals (the intervals between successive nesting years) than larger females. We hypothesized that this is attributed to the size-related foraging dichotomy, and calculated energy budgets and food requirements for the small and large females. Total reproductive energy costs for the small and large females were 1003 and 434 MJ, equivalent to 4043 kg of planktonic items and 275 kg of benthic items, respectively. The minimum durations necessary for accumulating the total reproductive energy for the small and large females were 430 and 26 days, equivalent to remigration intervals of 2 years and 1 year taking into account the nesting and migration durations and seasonal reproduction. Therefore, it was theoretically demonstrated that the intrapopulation variation in remigration intervals for Japanese loggerheads could be caused by the difference in their feeding habits, implying that remigration dynamics in a sea turtle population that shows a foraging dichotomy is regulated by feeding conditions not in a single habitat but in multiple habitats.

scholarly journals Spatial distribution of epibionts on olive ridley sea turtles at Playa Ostional, Costa Rica

2019 ◽  
Author(s):  
Nathan J. Robinson ◽  
Emily Lazo-Wasem ◽  
Brett O. Butler ◽  
Eric A. Lazo-Wasem ◽  
John D. Zardus ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Sea Turtles ◽  
Sea Turtle ◽  
The Body ◽  
Olive Ridley ◽  
Quantitative Characterization ◽  
Lepidochelys Olivacea ◽  
Almost All ◽  
Full Body

ABSTRACTThere is a wealth of published information on the epibiont communities of sea turtles, yet many of these studies have exclusively sampled epibionts found only on the carapace. Considering that epibionts may be found on almost all body-surfaces and that it is highly plausible to expect different regions of the body to host distinct epibiont taxa, there is a need for quantitative comparative studies to investigate spatial variation in the epibiont communities of turtles. To achieve this, we measured how total epibiont abundance and biomass on olive ridley turtles Lepidochelys olivacea varies among four body-areas of the hosts (n = 30). We show that epibiont loads on olive ridleys are higher, both in terms of number and biomass, on the skin than they are on the carapace or plastron. This contrasts with previous findings for other hard-shelled sea turtles, where epibionts are usually more abundant on the carapace. Moreover, the arguably most ubiquitous epibiont taxon for other hard-shelled sea turtles, the barnacle Chelonibia spp., only occurs in relatively low numbers on olive ridleys, while the barnacles Stomatolepas elegans and Platylepas hexastylos are far more abundant. We postulate that these differences between the epibiont communities of different sea turtle taxa could indicate that the carapaces of olive ridley turtles provide a more challenging substratum for epibionts than do the hard shells of other sea turtles. In addition, we conclude that it is important to conduct full body surveys when attempting to produce a holistic qualitative or quantitative characterization of the epibiont communities of sea turtles.

Monitoring green sea turtles in Brazilian feeding areas: relating body condition index to fibropapillomatosis prevalence

2019 ◽  
Vol 99 (8) ◽  
pp. 1879-1887 ◽  
Author(s):  
Silmara Rossi ◽  
Angélica María Sánchez-Sarmiento ◽  
Robson Guimarães dos Santos ◽  
Roberta Ramblas Zamana ◽  
Fabiola Eloisa Setim Prioste ◽  
...  
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Condition Index ◽  
Sea Turtle ◽  
The Body ◽  
Body Condition Index ◽  
Green Sea Turtles ◽  
Green Turtles

AbstractFibropapillomatosis (FP) can be an important conservation threat to green sea turtles (Chelonia mydas) due to its widespread distribution and complex aetiology. Thus, understanding the impacts of FP in sea turtle populations is a research priority towards conservation efforts. The body condition index (BCI), based on straight carapace length (SCL) and body mass (BM), is an accurate indicator of body-nutritional condition that can be used in routine green turtle health evaluations. This study aimed to compare BCI in FP-free (N = 369) and FP-affected (N = 518) green turtles from Brazilian feeding areas. Body condition indices were evaluated in terms of the South-west Atlantic Fibropapillomatosis Score – FPSSWA (mild, moderate and severe), study sites (five Brazilian states), origin (intentional capture, fishery, stranding and afloat) and sex (when known). Curved and straight carapace lengths, and body mass were recorded in order to calculate BCI. Statistical analysis revealed significant differences in BCI among green turtles from different study areas (P = 0.02), and lower BCI values in FP-free than in FP-positive individuals (P < 0.0001). With regards to origin, the highest BCI was found in the intentional capture group (N = 245; 1.47 ± 0.16), followed by fishery (N = 180; 1.46 ± 0.20). Analysis according to sex revealed a higher mean BCI among females than males (P < 0.017). This study provides relevant data on the health and nutritional status of green turtles along the Brazilian coast, in important feeding areas for this species.

scholarly journals Beetle-bearing coprolites possibly reveal the diet of a Late Triassic dinosauriform

2019 ◽  
Vol 6 (3) ◽  
pp. 181042 ◽  
Author(s):  
Martin Qvarnström ◽  
Joel Vikberg Wernström ◽  
Rafał Piechowski ◽  
Mateusz Tałanda ◽  
Per E. Ahlberg ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Small Animal ◽  
The Body ◽  
Late Triassic ◽  
Gut Contents ◽  
Host Animal ◽  
Terrestrial Invertebrates ◽  
Large Size ◽  
Body Fossil ◽  
Synchrotron Microtomography

Diets of extinct animals can be difficult to analyse if no direct evidence, such as gut contents, is preserved in association with body fossils. Inclusions from coprolites (fossil faeces), however, may also reflect the diet of the host animal and become especially informative if the coprolite producer link can be established. Here we describe, based on propagation phase-contrast synchrotron microtomography (PPC-SRμCT), the contents of five morphologically similar coprolites collected from two fossil-bearing intervals from the highly fossiliferous Upper Triassic locality at Krasiejów in Silesia, Poland. Beetle remains, mostly elytra, and unidentified exoskeleton fragments of arthropods are the most conspicuous inclusions found in the coprolites. The abundance of these inclusions suggests that the coprolite producer deliberately targeted beetles and similar small terrestrial invertebrates as prey, but the relatively large size of the coprolites shows that it was not itself a small animal. The best candidate from the body fossil record of the locality is the dinosauriform Silesaurus opolensis Dzik, 2003, which had an anatomy in several ways similar to those of bird-like neotheropod dinosaurs and modern birds. We hypothesize that the beak-like jaws of S. opolensis were used to efficiently peck small insects off the ground, a feeding behaviour analogous to some extant birds.

scholarly journals Congenital Malformations in Sea Turtles: Puzzling Interplay between Genes and Environment

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 444
Author(s):  
Rodolfo Martín-del-Campo ◽  
María Fernanda Calderón-Campuzano ◽  
Isaías Rojas-Lleonart ◽  
Raquel Briseño-Dueñas ◽  
Alejandra García-Gasca
Keyword(s):  
Congenital Malformations ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
The Body ◽  
Embryonic Mortality ◽  
Olive Ridley ◽  
Mexican Pacific ◽  
Regulatory Pathways ◽  
Genes And Environment

The completion of embryonic development depends, in part, on the interplay between genetic factors and environmental conditions, and any alteration during development may affect embryonic genetic and epigenetic regulatory pathways leading to congenital malformations, which are mostly incompatible with life. Oviparous reptiles, such as sea turtles, that produce numerous eggs in a clutch that is buried on the beach provide an opportunity to study embryonic mortality associated with malformations that occur at different times during development, or that prevent the hatchling from emerging from the nest. In sea turtles, the presence of congenital malformations frequently leads to mortality. A few years ago, a detailed study was performed on external congenital malformations in three species of sea turtles from the Mexican Pacific and Caribbean coasts, the hawksbill turtle, Eretmochelys imbricata (n = 23,559 eggs), the green turtle, Chelonia mydas (n = 17,690 eggs), and the olive ridley, Lepidochelys olivacea (n = 20,257 eggs), finding 63 types of congenital malformations, of which 38 were new reports. Of the three species, the olive ridley showed a higher incidence of severe anomalies in the craniofacial region (49%), indicating alterations of early developmental pathways; however, several malformations were also observed in the body, including defects in the carapace (45%) and limbs (33%), as well as pigmentation disorders (20%), indicating that deviations occurred during the middle and later stages of development. Although intrinsic factors (i.e., genetic mutations or epigenetic modifications) are difficult to monitor in the field, some environmental factors (such as the incubation temperature, humidity, and probably the status of feeding areas) are, to some extent, less difficult to monitor and/or control. In this review, we describe the aetiology of different malformations observed in sea turtle embryos, and provide some actions that can reduce embryonic mortality.

Feeding ecology of Symbolophorus californiensis larvae (Teleostei: Myctophidae) in the southern transition region of the western North Pacific

2009 ◽  
Vol 90 (6) ◽  
pp. 1249-1256 ◽  
Author(s):  
Chiyuki Sassa
Keyword(s):  
Transition Region ◽  
North Pacific ◽  
Western North Pacific ◽  
Developmental Stages ◽  
Feeding Habits ◽  
Larval Growth ◽  
Trophic Niche ◽  
Size Class ◽  
Gut Contents ◽  
Wide Range

The feeding habits of myctophid larvae of Symbolophorus californiensis were examined in the southern transition region of the western North Pacific where the main spawning and nursery grounds of S. californiensis are formed. This species is a key component of the pelagic ecosystems of this region, and their larvae attain one of the largest sizes among myctophids. To analyse gut contents larvae, including most life history stages after yolk-sac absorption (3.7 to 22.2 mm body length (BL)), were collected in the upper 100 m layer in 1997 and 1998. Feeding incidence was higher during the day than at night (53.1–92.3% versus 0–5.6%), and daytime feeding incidence increased gradually with larval growth. Larvae fed mainly on copepods of various developmental stages. Larvae of S. californiensis showed an ontogenetic change in their diet: larvae ≤7.9 mm BL (i.e. preflexion stage) fed mainly on copepod eggs and nauplii, while the larvae ≥8 mm BL consumed mainly calanoid copepodites such as Pseudocalanus and Paracalanus spp. In the largest size-class (16–22.2 mm BL), the furcilia stage of euphausiids was also an important prey item. There was an increase in the average prey size with growth in larvae ≤11.9 mm BL, while the number of prey eaten positively correlated with growth in larvae ≥12 mm BL. The trophic niche breadth also increased with larval growth, which would ensure a wide range of available food resources for the larger size-class larvae.

scholarly journals Feeding activity and diet composition of round goby (Neogobius melanostomus, Pallas 1814) in the coastal waters of SE Baltic Sea

2015 ◽  
Vol 44 (4) ◽  
Author(s):  
Artūras Skabeikis ◽  
Jūratė Lesutienė
Keyword(s):  
Baltic Sea ◽  
Coastal Waters ◽  
Diet Composition ◽  
Feeding Activity ◽  
Macoma Balthica ◽  
Round Goby ◽  
Benthic Fauna ◽  
Neogobius Melanostomus ◽  
The Body ◽  
Gut Contents

AbstractFeeding activity and diet composition of round goby were investigated in the south-eastern Baltic Sea, the Lithuanian coastal waters during May-October 2012 in order to determine main feeding objects and seasonal periods when native fauna could be most affected by predation of this highly invasive species. In total, prey represented by 18 taxa was found in the gut contents of dissected fish. Feeding activity of round goby varied depending on the body size, sex and stage of the reproduction period. The gut contents of < 50 mm specimens were dominated by zooplanktonic and meiobenthic organisms, whereas larger individuals (50–99 mm) shifted to amphipods and mollusks. Individuals of the intermediate 100-200 mm length had a variable diet, changing depending on the season; in spring they mostly preyed on Macoma balthica, in summer − on polychaetes, while in autumn the contribution of Mytilus trossulus and fish considerably increased in their diet. Diet composition of individuals ≥ 200 mm was relatively constant in the course of the study with substantial preference to M. balthica. These findings imply that benthic fauna, particularly a newly settled generation of epibenthic mollusks in autumn is under strong predatory pressure of the round goby.

Galapagos Tortoises and Sea Turtles in Gold Rush-Era California

2014 ◽  
Vol 91 (2) ◽  
pp. 20-39 ◽  
Author(s):  
Cyler Conrad ◽  
Allen Pastron
Keyword(s):  
San Francisco ◽  
Native Species ◽  
Sea Turtles ◽  
Rare Event ◽  
Legal Protection ◽  
Sea Turtle ◽  
Gold Rush ◽  
Late Nineteenth Century ◽  
Scientific Curiosity ◽  
Native Populations

Spotting a sea turtle or Galapagos tortoise on the early wharfs and streets of San Francisco or Sacramento, California during the Gold Rush (1848-1855) would not have been a rare event. Massive population influx into the San Francisco Bay region during this time resulted in substantial impacts to native species and habitats of all taxa, but the demand for food resulted in many resources, turtles and tortoises included, being imported into the cities. Providing a fresh and delectable food source, these terrapin were brought to San Francisco and Sacramento to feed the hungry Gold Rush populous. Their taste, popularity and demand also resulted in small numbers being imported into gold mining towns in the San Joaquin Valley and foothills of the Sierra Nevada’s. Remarkable as this process was, the consumption and importation of both sea turtles and Galapagos tortoises during the Gold Rush pushed native populations of these species to the brink of extinction during the mid to late-nineteenth century. Declining numbers of terrapin and increased scientific curiosity, with a desire to safeguard these creatures for future generations, resulted in their eventually legal protection and conservation. In many ways the impacts of the decimation of terrapin in the eastern Pacific during the Gold Rush are still felt today, as conservation and breeding efforts continue in an attempt to return native turtle and tortoise populations to pre-Euro-American contact levels. This research describes the historical, and new archaeofaunal, evidence of the terrapin import market in San Francisco, Sacramento and beyond during the dynamic period of the California Gold Rush.

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