Cynthia G. Norton, Angela F. Johnson, Betsy M. Nelson
Abstract: In many species, the difference between pigmented and non-pigmented individuals is due to a single recessive Mendelian gene. We have demonstrated that this is also the case in the freshwater hermaphroditic snail, Planorbella trivolvis (Say, 1817), and established an albino population with comparable genetic background to a wild population so that pigmentation can be used as a visible genetic marker to better understand the reproductive biology of these mollusks. We carried out Mendelian crosses between albino (A) individuals from an inbred laboratory strain and pigmented (P) individuals one generation removed from a natural population and assessed pigmentation of progeny from eggs collected immediately after mating and 11 weeks later. Results of parental, F1, and F2 generations and backcrosses to pure-breeding albinos were consistent with a Mendelian single gene inheritance pattern. Because we never observed albino progeny from any albino snails mated to pigmented sperm donors, we also confirmed that selfing is rare in P. trivolvis. A simple non-invasive paternity marker in this unusual hermaphrodite snail that displays almost no self-fertilization will facilitate experiments to understand its reproductive biology and provide a more complete picture of hermaphrodite mating strategies.
{"title":"The Genetic Basis of Albinism in the Hermaphroditic Freshwater Snail Planorbella trivolvis","authors":"Cynthia G. Norton, Angela F. Johnson, Betsy M. Nelson","doi":"10.4003/006.036.0110","DOIUrl":"https://doi.org/10.4003/006.036.0110","url":null,"abstract":"Abstract: \u0000 In many species, the difference between pigmented and non-pigmented individuals is due to a single recessive Mendelian gene. We have demonstrated that this is also the case in the freshwater hermaphroditic snail, Planorbella trivolvis (Say, 1817), and established an albino population with comparable genetic background to a wild population so that pigmentation can be used as a visible genetic marker to better understand the reproductive biology of these mollusks. We carried out Mendelian crosses between albino (A) individuals from an inbred laboratory strain and pigmented (P) individuals one generation removed from a natural population and assessed pigmentation of progeny from eggs collected immediately after mating and 11 weeks later. Results of parental, F1, and F2 generations and backcrosses to pure-breeding albinos were consistent with a Mendelian single gene inheritance pattern. Because we never observed albino progeny from any albino snails mated to pigmented sperm donors, we also confirmed that selfing is rare in P. trivolvis. A simple non-invasive paternity marker in this unusual hermaphrodite snail that displays almost no self-fertilization will facilitate experiments to understand its reproductive biology and provide a more complete picture of hermaphrodite mating strategies.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0110","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46937517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Population density commonly affects snail biology and is an important ecological factor to consider in any pest control program because population growth rates can be affected. Lissachatina fulica (Bowdich, 1822) is a pest of plants throughout the worldwide tropics; however, its biology is not completely known. We studied the effects of three rearing densities: low (5 snails per 25 × 38 × 17 cm (L × W × H) cage), medium (15 snails), or high (35 snails), on L. fulica growth, reproduction, and survival. High rearing density reduced growth, affected the initiation of egg laying, and reduced the number of eggs laid per snail and per clutch. Mortality did not increase with high rearing density, nor was any cannibalism observed, even when snails were deprived of food. Juvenile snail survival was more affected by lack of food than was adult survival, and availability of calcium did not compensate for lack of food. High-density rearing effects were not likely caused by limited food, calcium, or oxygen.
{"title":"Effects of Density and Food Deprivation on Growth, Reproduction, and Survival of Lissachatina fulica","authors":"Katrina L. Dickens, J. Capinera, T. Smith","doi":"10.4003/006.036.0115","DOIUrl":"https://doi.org/10.4003/006.036.0115","url":null,"abstract":"Abstract: Population density commonly affects snail biology and is an important ecological factor to consider in any pest control program because population growth rates can be affected. Lissachatina fulica (Bowdich, 1822) is a pest of plants throughout the worldwide tropics; however, its biology is not completely known. We studied the effects of three rearing densities: low (5 snails per 25 × 38 × 17 cm (L × W × H) cage), medium (15 snails), or high (35 snails), on L. fulica growth, reproduction, and survival. High rearing density reduced growth, affected the initiation of egg laying, and reduced the number of eggs laid per snail and per clutch. Mortality did not increase with high rearing density, nor was any cannibalism observed, even when snails were deprived of food. Juvenile snail survival was more affected by lack of food than was adult survival, and availability of calcium did not compensate for lack of food. High-density rearing effects were not likely caused by limited food, calcium, or oxygen.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0115","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43240274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Burnett, K. Pope, A. Wong, C. Allen, Danielle M. Haak, B. Stephen, D. R. Uden
Abstract: The Chinese mystery snail, Bellamya chinensis (Gray, 1834) is a gastropod native to East Asia and is considered an invasive species in North America where its impacts on native species and ecosystems are not well understood. Scientific literature describing its biology and life history are sparse. Thermal tolerance limits, or the maximum and minimum temperature under which a species can survive, are key to identifying the potential geographical range of a species. The ability of managers to control invasive species is directly impacted by the thermal tolerance limits of a species. We attempted to identify the thermal tolerance limits of B. chinensis in a laboratory setting. Using a random sampling design, we exposed groups of wild-caught B. chinensis to either extreme high or low temperature treatments. We identified the upper temperature tolerance limit as between 40 and 45 °C. This result indicates some hot water management techniques may successfully prevent spread of B. chinensis among waterways. Despite exposing B. chinensis to freezing temperatures for extended periods of time we did not identify a lower temperature limit. Identifying the thermal tolerance limits of this and other invasive species informs predictions of range expansion and identification of potential prevention efforts.
{"title":"Thermal Tolerance Limits of the Chinese Mystery Snail (Bellamya chinensis): Implications for Management","authors":"J. Burnett, K. Pope, A. Wong, C. Allen, Danielle M. Haak, B. Stephen, D. R. Uden","doi":"10.4003/006.036.0106","DOIUrl":"https://doi.org/10.4003/006.036.0106","url":null,"abstract":"Abstract: The Chinese mystery snail, Bellamya chinensis (Gray, 1834) is a gastropod native to East Asia and is considered an invasive species in North America where its impacts on native species and ecosystems are not well understood. Scientific literature describing its biology and life history are sparse. Thermal tolerance limits, or the maximum and minimum temperature under which a species can survive, are key to identifying the potential geographical range of a species. The ability of managers to control invasive species is directly impacted by the thermal tolerance limits of a species. We attempted to identify the thermal tolerance limits of B. chinensis in a laboratory setting. Using a random sampling design, we exposed groups of wild-caught B. chinensis to either extreme high or low temperature treatments. We identified the upper temperature tolerance limit as between 40 and 45 °C. This result indicates some hot water management techniques may successfully prevent spread of B. chinensis among waterways. Despite exposing B. chinensis to freezing temperatures for extended periods of time we did not identify a lower temperature limit. Identifying the thermal tolerance limits of this and other invasive species informs predictions of range expansion and identification of potential prevention efforts.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43018547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Robert Robertson (1934–2018) was systematic malacologist, natural historian, and reproductive biologist, focusing on marine gastropods and based at the Academy of Natural Sciences in Philadelphia (ANSP) for most of his career. An account of his professional life is presented, based in part on a brief autobiography here included. Lists of his 142 publications (published and unpublished, formal and informal) and 13 taxa, as well as taxa named for him and publications written about him, are provided.
{"title":"Robert Robertson (1934–2018): His Career, Taxa, and Bibliography","authors":"P. Mikkelsen, R. Bieler","doi":"10.4003/006.036.0116","DOIUrl":"https://doi.org/10.4003/006.036.0116","url":null,"abstract":"Abstract: \u0000 Robert Robertson (1934–2018) was systematic malacologist, natural historian, and reproductive biologist, focusing on marine gastropods and based at the Academy of Natural Sciences in Philadelphia (ANSP) for most of his career. An account of his professional life is presented, based in part on a brief autobiography here included. Lists of his 142 publications (published and unpublished, formal and informal) and 13 taxa, as well as taxa named for him and publications written about him, are provided.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0116","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47292889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cynthia G. Norton, Angela F. Johnson, Betsy M. Nelson
Abstract: Fecundity in outcrossing species can be influenced by both maternal and paternal parents. To tease out these influences, we observed egg production in two populations of the hermaphroditic freshwater snail, Planorbella trivolvis (Say 1817). We carried out both intra- and inter-population matings between individuals from an inbred albino laboratory strain and individuals one generation removed from a natural population, and measured egg production for two 3-week periods - immediately after mating and 11 weeks later. In the female role, individuals from the albino laboratory population produced significantly more egg masses than the wild derived snails, regardless of whether they were mated to a partner of wild or laboratory origin, indicating that egg mass production is controlled by the maternal parent. Conversely, regardless of their own origin (laboratory or wild), snails mated to individuals from the wild derived population laid more eggs in each egg mass than those fertilized by sperm from the lab population. These results indicate that the number of egg masses a snail lays is determined at least in part by a maternal contribution, and that the number of eggs deposited in each mass may be influenced by the origin of the sperm donor. In addition, we confirmed a short-term trade-off between growth and reproduction as differences in egg production among mating types were mirrored by differences in body size. Further investigation into the nature of these differences will lead to better understanding of the reproductive biology of these hermaphrodite mollusks.
{"title":"Population Differences in Fecundity Components in the Hermaphroditic Freshwater Snail Planorbella trivolvis","authors":"Cynthia G. Norton, Angela F. Johnson, Betsy M. Nelson","doi":"10.4003/006.036.0109","DOIUrl":"https://doi.org/10.4003/006.036.0109","url":null,"abstract":"Abstract: \u0000 Fecundity in outcrossing species can be influenced by both maternal and paternal parents. To tease out these influences, we observed egg production in two populations of the hermaphroditic freshwater snail, Planorbella trivolvis (Say 1817). We carried out both intra- and inter-population matings between individuals from an inbred albino laboratory strain and individuals one generation removed from a natural population, and measured egg production for two 3-week periods - immediately after mating and 11 weeks later. In the female role, individuals from the albino laboratory population produced significantly more egg masses than the wild derived snails, regardless of whether they were mated to a partner of wild or laboratory origin, indicating that egg mass production is controlled by the maternal parent. Conversely, regardless of their own origin (laboratory or wild), snails mated to individuals from the wild derived population laid more eggs in each egg mass than those fertilized by sperm from the lab population. These results indicate that the number of egg masses a snail lays is determined at least in part by a maternal contribution, and that the number of eggs deposited in each mass may be influenced by the origin of the sperm donor. In addition, we confirmed a short-term trade-off between growth and reproduction as differences in egg production among mating types were mirrored by differences in body size. Further investigation into the nature of these differences will lead to better understanding of the reproductive biology of these hermaphrodite mollusks.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0109","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48723418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. López-Peraza, M. Hernández-Rodríguez, B. Barón-Sevilla
Abstract: Cephalopods are infested by a wide variety of internal and external parasites, and although they have the ability to remove them, this ability may be limited when a high parasitic load occurs. Additionally, when the parasite is harmful, it may cause adverse effects on the health of the host and even death if not timely eliminated. Several treatments have been applied to eliminate the parasites in cephalopods but few have proved to be effective. This study examines an effective treatment for the elimination of the leech Stibarobdela moorei present in the epidermis of the adult of Octopus bimaculatus (Verril, 1883) captured in the Mexican Pacific Ocean, which, if used properly, does not have any side effects on humans or organisms in cultivation. The treatment consists of immersions in seawater with clove oil at a concentration of 0.45 ml l-1 for two minutes; the advantage is that it can be applied as often as necessary until the leeches are eliminated completely from the octopods. It is recommended that the treatment be applied with a minimum interval of 3 days between each application with the purpose of reducing the stress of the octopuses, caused by the manipulation.
摘要:头足类动物受到各种内外寄生虫的侵袭，尽管它们有清除这些寄生虫的能力，但当寄生负荷较高时，这种能力可能会受到限制。此外，当寄生虫有害时，如果不及时消灭，可能会对宿主的健康造成不良影响，甚至死亡。已经应用了几种方法来消除头足类动物中的寄生虫，但很少被证明是有效的。本研究探讨了一种消除墨西哥太平洋捕获的双斑章鱼(Verril, 1883)成体表皮中存在的水蛭的有效治疗方法，如果使用得当，对人体或养殖中的生物没有任何副作用。该处理包括将丁香油浸入浓度为0.45 ml -1的海水中两分钟;这样做的好处是，只要有必要，就可以随时使用，直到水蛭从章鱼身上完全消灭为止。建议每次应用之间至少间隔3天，以减少由操作引起的章鱼压力。
{"title":"Protocol for Removal of the Marine Leech Stibarobdella moorei (Oka, 1910) from the Two-Spotted Octopus, Octopus bimaculatus (Verril, 1883)","authors":"D. López-Peraza, M. Hernández-Rodríguez, B. Barón-Sevilla","doi":"10.4003/006.036.0105","DOIUrl":"https://doi.org/10.4003/006.036.0105","url":null,"abstract":"Abstract: Cephalopods are infested by a wide variety of internal and external parasites, and although they have the ability to remove them, this ability may be limited when a high parasitic load occurs. Additionally, when the parasite is harmful, it may cause adverse effects on the health of the host and even death if not timely eliminated. Several treatments have been applied to eliminate the parasites in cephalopods but few have proved to be effective. This study examines an effective treatment for the elimination of the leech Stibarobdela moorei present in the epidermis of the adult of Octopus bimaculatus (Verril, 1883) captured in the Mexican Pacific Ocean, which, if used properly, does not have any side effects on humans or organisms in cultivation. The treatment consists of immersions in seawater with clove oil at a concentration of 0.45 ml l-1 for two minutes; the advantage is that it can be applied as often as necessary until the leeches are eliminated completely from the octopods. It is recommended that the treatment be applied with a minimum interval of 3 days between each application with the purpose of reducing the stress of the octopuses, caused by the manipulation.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0105","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43348453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. M. González, B. Lavaniegos, J. G. Valdés, Martín E. De La Cruz Orozco
Abstract: There are few studies on pelagic mollusks from the California Current, despite their ecological importance and vulnerability to climate change (e.g., ocean acidification and hypoxia). We analyzed abundances of holoplanktonic mollusks during three years (2006–2008) along a transect-line parallel to the Baja California coast. The main differences in physical factors were increasing temperature and salinity from north to south, and lower dissolved oxygen concentration south of Punta Eugenia (28°N). The lowest oxygen concentrations occurred in summer, with hypoxic conditions (< 0.5 ml · L-1) in the upper 100 m depth at some locations. Planktonic mollusk abundance did not differ along the latitudinal gradient, excepting Desmopterus pacificus Essenberg, 1919 and individuals from the genus Pterotrachea Forskal, 1775. In contrast, the temporal variability was high, mainly in a seasonal scale but also among years. The influence of El Niño 2006–2007 and La Niña 2007–2008 were evident by a sharp increase of Corolla spectabilis Dall, 1871 in April 2007 during the El Niño-La Niña transition. During 2008, pelagic mollusks remained with moderate abundance in winter-spring despite the high chlorophyll concentrations recorded (up to 3.26 mg · m-3). Subsequently, during the relaxation of a first pulse of La Niña in July 2008, there was a rebound in the abundance of the heteropod Atlanta Lesueur, 1817. and individuals in the Order Gymnosomata. The oxygen gradient inversely influenced mollusk abundance in most of the genera (Clio Linnaeus, 1767, Limacina Bosc, 1817, Atlanta, and Firoloida Lesueur, 1817) and the order Gymnosomata, but for Cavolinia Abildgaard, 1791, Creseis Rang, 1828, Desmopterus, and Pterotrachea, the salinity gradient was more influential. Therefore, holoplanktonic mollusks genera were useful indicators of climatic variability.
{"title":"Holoplanktonic Mollusks off Western Baja California During the Weak El Niño 2006-07 and Further Transition to La Niña","authors":"O. M. González, B. Lavaniegos, J. G. Valdés, Martín E. De La Cruz Orozco","doi":"10.4003/006.036.0112","DOIUrl":"https://doi.org/10.4003/006.036.0112","url":null,"abstract":"Abstract: \u0000 There are few studies on pelagic mollusks from the California Current, despite their ecological importance and vulnerability to climate change (e.g., ocean acidification and hypoxia). We analyzed abundances of holoplanktonic mollusks during three years (2006–2008) along a transect-line parallel to the Baja California coast. The main differences in physical factors were increasing temperature and salinity from north to south, and lower dissolved oxygen concentration south of Punta Eugenia (28°N). The lowest oxygen concentrations occurred in summer, with hypoxic conditions (< 0.5 ml · L-1) in the upper 100 m depth at some locations. Planktonic mollusk abundance did not differ along the latitudinal gradient, excepting Desmopterus pacificus Essenberg, 1919 and individuals from the genus Pterotrachea Forskal, 1775. In contrast, the temporal variability was high, mainly in a seasonal scale but also among years. The influence of El Niño 2006–2007 and La Niña 2007–2008 were evident by a sharp increase of Corolla spectabilis Dall, 1871 in April 2007 during the El Niño-La Niña transition. During 2008, pelagic mollusks remained with moderate abundance in winter-spring despite the high chlorophyll concentrations recorded (up to 3.26 mg · m-3). Subsequently, during the relaxation of a first pulse of La Niña in July 2008, there was a rebound in the abundance of the heteropod Atlanta Lesueur, 1817. and individuals in the Order Gymnosomata. The oxygen gradient inversely influenced mollusk abundance in most of the genera (Clio Linnaeus, 1767, Limacina Bosc, 1817, Atlanta, and Firoloida Lesueur, 1817) and the order Gymnosomata, but for Cavolinia Abildgaard, 1791, Creseis Rang, 1828, Desmopterus, and Pterotrachea, the salinity gradient was more influential. Therefore, holoplanktonic mollusks genera were useful indicators of climatic variability.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0112","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Hernandez, A. Munguía-Vega, Fernanda Pérez-Alarcón, Francisco J. Fernández-Rivera-Melo, O. Angulo-Campillo
Abstract: A recent molecular study on pelagic nudibranchs showed that Glaucus marginatus (Reinhardt and Bergh, 1864) is a complex of three cryptic species, whereas the congener G. atlanticus (Forster, 1777) remain as one species. The objective of the present study was to determine the identity of pelagic nudibranchs collected in the Gulf of California using both molecular and traditional taxonomy. New DNA sequences (COI) and GenBank data were used to confirm the specimens' identity as G. atlanticus. Records from G. atlanticus were obtained from databases to determine the species geographic range. Present results increase that range northwards by approximately 150 km in the Gulf of California. Molecular data indicate that G. atlanticus from the Gulf has a wide infl uence from populations from the North and South Pacific and Indian Oceans. There is no current evidence of other cryptic species.
{"title":"Occurrence of Glaucus atlanticus in the Midriff Islands Region, Gulf of California, Mexico","authors":"L. Hernandez, A. Munguía-Vega, Fernanda Pérez-Alarcón, Francisco J. Fernández-Rivera-Melo, O. Angulo-Campillo","doi":"10.4003/006.036.0113","DOIUrl":"https://doi.org/10.4003/006.036.0113","url":null,"abstract":"Abstract: \u0000 A recent molecular study on pelagic nudibranchs showed that Glaucus marginatus (Reinhardt and Bergh, 1864) is a complex of three cryptic species, whereas the congener G. atlanticus (Forster, 1777) remain as one species. The objective of the present study was to determine the identity of pelagic nudibranchs collected in the Gulf of California using both molecular and traditional taxonomy. New DNA sequences (COI) and GenBank data were used to confirm the specimens' identity as G. atlanticus. Records from G. atlanticus were obtained from databases to determine the species geographic range. Present results increase that range northwards by approximately 150 km in the Gulf of California. Molecular data indicate that G. atlanticus from the Gulf has a wide infl uence from populations from the North and South Pacific and Indian Oceans. There is no current evidence of other cryptic species.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0113","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49181668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Anthropogenic impacts on marine environments can be far-reaching and variable, and in an effort to mitigate these impacts, marine protected areas (MPAs) have been established globally. Indirect effects of MPAs on marine food webs and consumer behavior can be revealed through the diet of generalist predators, like octopuses, since their diet is a reflection of both preference and prey availability. Octopuses (Octopus bimaculatus Verrill, 1883) and invertebrate prey species were collected around Santa Catalina Island, CA in the summer of 2012, 2013, and 2014, and muscle tissues were analyzed for δ13C and δ15N. The δ13C and δ15N signature of octopuses caught within the MPA area and the non-MPA area were compared within diet space. Estimated contribution of prey species to octopus diet was calculated using a Bayesian mixing model. Octopuses caught in MPA areas had significantly different isotopic signatures than octopuses caught outside MPA areas in 2012 and 2013, but not 2014. Prey contributions to diet were highly variable between areas and years. Bivalves were a consistent contributor to MPA octopus diet, and the large snail Megastrea undosa (W. Wood, 1828) made up a relatively large proportion of the diet of octopuses from all areas and years. Additionally, there were more moray eels, a nocturnal predator outside MPA areas but more diurnal predators inside MPA areas. These results suggest octopus foraging behavior could be influenced by variation in predation risk reveal an indirect impact of diurnal predator recovery in the MPA. To fully understand the impact of anthropogenic change on marine environments, we must assess changes in the entire community and the interactions that drive community function.
{"title":"Variation in Octopus bimaculatus Verrill, 1883 Diet as Revealed through δ13C and δ15N Stable Isotope Analysis: Potential Indirect Effects of Marine Protected Areas","authors":"Jennifer K. K. Hofmeister","doi":"10.4003/006.036.0103","DOIUrl":"https://doi.org/10.4003/006.036.0103","url":null,"abstract":"Abstract: Anthropogenic impacts on marine environments can be far-reaching and variable, and in an effort to mitigate these impacts, marine protected areas (MPAs) have been established globally. Indirect effects of MPAs on marine food webs and consumer behavior can be revealed through the diet of generalist predators, like octopuses, since their diet is a reflection of both preference and prey availability. Octopuses (Octopus bimaculatus Verrill, 1883) and invertebrate prey species were collected around Santa Catalina Island, CA in the summer of 2012, 2013, and 2014, and muscle tissues were analyzed for δ13C and δ15N. The δ13C and δ15N signature of octopuses caught within the MPA area and the non-MPA area were compared within diet space. Estimated contribution of prey species to octopus diet was calculated using a Bayesian mixing model. Octopuses caught in MPA areas had significantly different isotopic signatures than octopuses caught outside MPA areas in 2012 and 2013, but not 2014. Prey contributions to diet were highly variable between areas and years. Bivalves were a consistent contributor to MPA octopus diet, and the large snail Megastrea undosa (W. Wood, 1828) made up a relatively large proportion of the diet of octopuses from all areas and years. Additionally, there were more moray eels, a nocturnal predator outside MPA areas but more diurnal predators inside MPA areas. These results suggest octopus foraging behavior could be influenced by variation in predation risk reveal an indirect impact of diurnal predator recovery in the MPA. To fully understand the impact of anthropogenic change on marine environments, we must assess changes in the entire community and the interactions that drive community function.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49248610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Rumina decollata (Linnaeus 1758) is native to the Mediterranean region of Europe and north Africa. The first report in Argentina was in 1988 in Buenos Aires. In 2007, it was found in La Pampa and Mendoza. Here, we report its presence in Córdoba, extending its distributional range northwards more than 600 km. This finding is significant given that Rumina decollata is a facilitative predator and can deleteriously impact mollusk assembles causing ecological imbalances.
{"title":"First Report of the Non-Native Snail Rumina decollata (Linnaeus, 1758) (Subulinidae: Gastropoda) in Córdoba (Argentina): Implications for Biodiversity and Human Health","authors":"P. Reyna, Sandra Gordillo","doi":"10.4003/006.036.0108","DOIUrl":"https://doi.org/10.4003/006.036.0108","url":null,"abstract":"Abstract: \u0000 Rumina decollata (Linnaeus 1758) is native to the Mediterranean region of Europe and north Africa. The first report in Argentina was in 1988 in Buenos Aires. In 2007, it was found in La Pampa and Mendoza. Here, we report its presence in Córdoba, extending its distributional range northwards more than 600 km. This finding is significant given that Rumina decollata is a facilitative predator and can deleteriously impact mollusk assembles causing ecological imbalances.","PeriodicalId":7779,"journal":{"name":"American Malacological Bulletin","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4003/006.036.0108","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48681348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：