Pub Date : 2022-01-02DOI: 10.1080/13235818.2022.2035889
Tristan Joseph Verhoeff, S. O'shea
ABSTRACT New deep-sea cirrate octopuses (Octopoda: Cirrata) are reported from around Australia and New Zealand. The limited collections comprise three species, one that is for the first time reported from Australian waters, and one from each of Australia and New Zealand that we deem to be new to science. Taxonomic instability and regional taxonomic novelty preclude the unambiguous attribution of any species to genus. While we consider no species to be sibling, or even closely related, each is attributed to Grimpoteuthis: G. greeni n. sp., based on three specimens from southern Australia; G. angularis n. sp., based on a single specimen from New Zealand; and the first male specimen of G. abyssicola O’Shea, 1999, formerly known from the central Tasman Sea, which we describe and extend the distribution of into Australian waters. Relationships between these taxa and others provisionally attributed to the Grimpoteuthididae O’Shea, 1999 are evaluated and based primarily on the morphology of the shell, and secondarily on that of the gill, we propose a preliminary division of Grimpoteuthis sensu lato into three sensu lato morphologies. Publication LSID: lsid:http://zoobank.org:pub:92ACA16A-CB40-4254-BF7A-EAB25977AA92
{"title":"New records and two new species of Grimpoteuthis (Octopoda: Cirrata: Grimpoteuthididae) from southern Australia and New Zealand","authors":"Tristan Joseph Verhoeff, S. O'shea","doi":"10.1080/13235818.2022.2035889","DOIUrl":"https://doi.org/10.1080/13235818.2022.2035889","url":null,"abstract":"ABSTRACT New deep-sea cirrate octopuses (Octopoda: Cirrata) are reported from around Australia and New Zealand. The limited collections comprise three species, one that is for the first time reported from Australian waters, and one from each of Australia and New Zealand that we deem to be new to science. Taxonomic instability and regional taxonomic novelty preclude the unambiguous attribution of any species to genus. While we consider no species to be sibling, or even closely related, each is attributed to Grimpoteuthis: G. greeni n. sp., based on three specimens from southern Australia; G. angularis n. sp., based on a single specimen from New Zealand; and the first male specimen of G. abyssicola O’Shea, 1999, formerly known from the central Tasman Sea, which we describe and extend the distribution of into Australian waters. Relationships between these taxa and others provisionally attributed to the Grimpoteuthididae O’Shea, 1999 are evaluated and based primarily on the morphology of the shell, and secondarily on that of the gill, we propose a preliminary division of Grimpoteuthis sensu lato into three sensu lato morphologies. Publication LSID: lsid:http://zoobank.org:pub:92ACA16A-CB40-4254-BF7A-EAB25977AA92","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"42 1","pages":"4 - 30"},"PeriodicalIF":1.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43624359","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}
Pub Date : 2022-01-02DOI: 10.1080/13235818.2022.2036308
R. Nakayama, T. Nakano, A. Asakura
ABSTRACT Substrate variety and host preference of the epizoic limpet Lottia tenuisculpta were investigated based on specimen and field observations. Specimen observation revealed the presence of the limpet on 33 species of Mollusca and two species of Crustacea, and it predominantly used Tegulidae and Muricidae throughout its geographic range. Some of the substrate molluscs had radula traces and home scars probably engraved by L. tenuisculpta. Field observations conducted on the rocky shore of Shirahama, Wakayama, Japan, revealed the presence of L. tenuisculpta on 12 species of molluscs. The tegulid Omphalius nigerrimus and the muricid Reishia clavigera were its major substrates in the locality. The results of both sets of observations suggest that L. tenuisculpta is a host-general facultative epizoite and its host preference is family-specific. The choice of host species by L. tenuisculpta might be determined by the abundance and morphological and biological restrictions of the preferred substrates in each locality. The host-general and facultative nature of the limpet allows it to show geographical host conversion and contribute to favouring epizoic behaviour. Home scars of L. tenuisculpta on the hosts suggest that the limpet inhabits the same individual of the substrate species for an extended period.
{"title":"Substrate variety and host preference of the epizoic limpet Lottia tenuisculpta (Patellogastropoda: Lottiidae)","authors":"R. Nakayama, T. Nakano, A. Asakura","doi":"10.1080/13235818.2022.2036308","DOIUrl":"https://doi.org/10.1080/13235818.2022.2036308","url":null,"abstract":"ABSTRACT Substrate variety and host preference of the epizoic limpet Lottia tenuisculpta were investigated based on specimen and field observations. Specimen observation revealed the presence of the limpet on 33 species of Mollusca and two species of Crustacea, and it predominantly used Tegulidae and Muricidae throughout its geographic range. Some of the substrate molluscs had radula traces and home scars probably engraved by L. tenuisculpta. Field observations conducted on the rocky shore of Shirahama, Wakayama, Japan, revealed the presence of L. tenuisculpta on 12 species of molluscs. The tegulid Omphalius nigerrimus and the muricid Reishia clavigera were its major substrates in the locality. The results of both sets of observations suggest that L. tenuisculpta is a host-general facultative epizoite and its host preference is family-specific. The choice of host species by L. tenuisculpta might be determined by the abundance and morphological and biological restrictions of the preferred substrates in each locality. The host-general and facultative nature of the limpet allows it to show geographical host conversion and contribute to favouring epizoic behaviour. Home scars of L. tenuisculpta on the hosts suggest that the limpet inhabits the same individual of the substrate species for an extended period.","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"42 1","pages":"31 - 40"},"PeriodicalIF":1.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45103540","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}
Pub Date : 2022-01-02DOI: 10.1080/13235818.2022.2028970
R. Sousa, J. Vasconcelos, I. Vera-Escalona, R. Riera
ABSTRACT Microbes associated with marine invertebrates play a key role in the physiological and biochemical processes of the host, and can be responsible for food-borne diseases in humans. Raw invertebrates are a common component of coastal gastronomy worldwide and their consumption could represent a potential risk to humans if their microbiome hosts infectious bacteria. However, these species’ microbiome composition is usually unknown. In this study, we sequenced the 16S gene to characterise the microbiome of the digestive system and gonads of the commercially-exploited sea snail Phorcus sauciatus from the Macaronesian islands and mainland Portugal. The goal was to identify bacteria that might pose a threat to humans. In total, 910 OTUs were identified, thirty-two of which were found to be classified as Risk level-1 and -2 species. Among these, twenty pathogenic bacterial strains were found in high relative abundance and identified as potential drivers of human diseases, including Micrococcus luteus and Serratia marcescens. Here, we discuss how our findings on the occurrence of these bacteria could seriously affect humans. Our results are relevant beyond the scope of this study, as this work might also pave the way for uncovering further implications on the raw consumption of other shellfish and invertebrate species.
{"title":"Occurrence of bacteria potentially pathogenic to humans in a harvested intertidal sea snail","authors":"R. Sousa, J. Vasconcelos, I. Vera-Escalona, R. Riera","doi":"10.1080/13235818.2022.2028970","DOIUrl":"https://doi.org/10.1080/13235818.2022.2028970","url":null,"abstract":"ABSTRACT Microbes associated with marine invertebrates play a key role in the physiological and biochemical processes of the host, and can be responsible for food-borne diseases in humans. Raw invertebrates are a common component of coastal gastronomy worldwide and their consumption could represent a potential risk to humans if their microbiome hosts infectious bacteria. However, these species’ microbiome composition is usually unknown. In this study, we sequenced the 16S gene to characterise the microbiome of the digestive system and gonads of the commercially-exploited sea snail Phorcus sauciatus from the Macaronesian islands and mainland Portugal. The goal was to identify bacteria that might pose a threat to humans. In total, 910 OTUs were identified, thirty-two of which were found to be classified as Risk level-1 and -2 species. Among these, twenty pathogenic bacterial strains were found in high relative abundance and identified as potential drivers of human diseases, including Micrococcus luteus and Serratia marcescens. Here, we discuss how our findings on the occurrence of these bacteria could seriously affect humans. Our results are relevant beyond the scope of this study, as this work might also pave the way for uncovering further implications on the raw consumption of other shellfish and invertebrate species.","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"42 1","pages":"41 - 49"},"PeriodicalIF":1.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48843500","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}
Pub Date : 2021-10-02DOI: 10.1080/13235818.2021.2007750
F. Wells, C. Bessey, M. M. Gagnon, J. Keesing, J. Prince
ABSTRACT In many, but not all, years a recurring population of the marine aplysiid Bursatella hirsuta occurs on an intertidal limestone platform stretching between Little Armstrong Bay and North Point at Rottnest Island, Western Australia. Using a transect/quadrat method, we measured densities of B. hirsuta during the austral summer of 2020/2021. No individuals were present in December 2020, but a population with a mean density of 16.5 ± 1.6 (SE) inds m−2 was present on 17 January 2021. Density was low in bare sand (2.6 ± 3.2 inds m−2) and in the seagrass Amphibolis antarctica (2.0 ± 1.4 inds m−2), high in mixed algae, mostly Phaeophyceae (18.2 ± 1.8 inds m−2) and greatest (27.2 ± 14.3 inds m−2) in a small number of quadrats with a mixture of sand and algae or sand and A. antarctica. The population was estimated at >600,000 individuals. The species was present in February but had disappeared by late March 2021. The population at Little Armstrong Bay and North Point provides a fertile opportunity for developing a better understanding of the biology of B. hirsuta and broader questions of boom-and-bust populations.
{"title":"A recurring population of the sea hare Bursatella hirsuta (Gastropoda: Aplysiidae) at Rottnest Island, Western Australia","authors":"F. Wells, C. Bessey, M. M. Gagnon, J. Keesing, J. Prince","doi":"10.1080/13235818.2021.2007750","DOIUrl":"https://doi.org/10.1080/13235818.2021.2007750","url":null,"abstract":"ABSTRACT In many, but not all, years a recurring population of the marine aplysiid Bursatella hirsuta occurs on an intertidal limestone platform stretching between Little Armstrong Bay and North Point at Rottnest Island, Western Australia. Using a transect/quadrat method, we measured densities of B. hirsuta during the austral summer of 2020/2021. No individuals were present in December 2020, but a population with a mean density of 16.5 ± 1.6 (SE) inds m−2 was present on 17 January 2021. Density was low in bare sand (2.6 ± 3.2 inds m−2) and in the seagrass Amphibolis antarctica (2.0 ± 1.4 inds m−2), high in mixed algae, mostly Phaeophyceae (18.2 ± 1.8 inds m−2) and greatest (27.2 ± 14.3 inds m−2) in a small number of quadrats with a mixture of sand and algae or sand and A. antarctica. The population was estimated at >600,000 individuals. The species was present in February but had disappeared by late March 2021. The population at Little Armstrong Bay and North Point provides a fertile opportunity for developing a better understanding of the biology of B. hirsuta and broader questions of boom-and-bust populations.","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"41 1","pages":"285 - 288"},"PeriodicalIF":1.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41738707","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}
Pub Date : 2021-10-02DOI: 10.1080/13235818.2021.1986203
Zheyu Chen, Adrienne Jochum
ABSTRACT Corrigendum to the paper, ‘A new species of land snail from the genus Diplommatina Benson, 1849 (Gastropoda, Caenogastropoda, Diplommatinidae) from Sikkim Himalaya, North East India’ published in Molluscan Research 41, 1–7, 2021 DOI: 10.1080/13235818.2021.1970352.
{"title":"Comments on “A new species of land snail from the genus Diplommatina Benson, 1849 (Gastropoda, Caenogastropoda, Diplommatinidae) from Sikkim Himalaya, North East India” by N. K. Das & N. A. Aravind, Molluscan Research 41 (3), 262–268, 2021","authors":"Zheyu Chen, Adrienne Jochum","doi":"10.1080/13235818.2021.1986203","DOIUrl":"https://doi.org/10.1080/13235818.2021.1986203","url":null,"abstract":"ABSTRACT Corrigendum to the paper, ‘A new species of land snail from the genus Diplommatina Benson, 1849 (Gastropoda, Caenogastropoda, Diplommatinidae) from Sikkim Himalaya, North East India’ published in Molluscan Research 41, 1–7, 2021 DOI: 10.1080/13235818.2021.1970352.","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"41 1","pages":"332 - 334"},"PeriodicalIF":1.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44223141","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}
Pub Date : 2021-10-02DOI: 10.1080/13235818.2021.2003513
K. K. Sajikumar, T. M. Najmudeen, N. Ragesh, N. S. Jeena, Summaya Rahuman, K. T. S. Sunil, G. Sasikumar, Kolliyil Sunilkumar Mohamed
ABSTRACT This paper describes a mated female of the giant form of purpleback flying squid Sthenoteuthis oualaniensis (545 mm dorsal mantle length and 5.46 kg body weight) caught in the Arabian Sea, with biological, morphological, and molecular descriptors. Based on the growth increments within statoliths, its age was found to be 203 days with a high growth rate of 2.68 mm DML/day. Its diet contained squids (72.3%) and fish (27.3%) with a high degree (70%) of cannibalism. The total fecundity of the individual was estimated as 702,240 eggs. Three species of parasites were found, two species of Platyhelminthes from the mantle cavity (Phyllobothrium sp. and Nybelinia sp.) and one of Nematoda from the stomach (Anisakis simplex). The COI barcode confirmed the identity of the giant form as S. oualaniensis, and the high genetic divergence (6.18–9.35%) that was observed between the current specimen and other forms from various oceans points to the probability that it might be a genetically distinct lineage from the northern Indian Ocean. The present record forms the southernmost (10°05′ N) record of the giant form of this flying squid.
摘要本文用生物学、形态学和分子描述符描述了一只在阿拉伯海捕获的巨大紫背飞乌贼（背鞘长545毫米，体重5.46公斤）的交配雌性。根据定子石内的生长增量，发现其年龄为203天，高生长率为2.68 mm DML/天。它的饮食中含有鱿鱼（72.3%）和鱼类（27.3%），其中自相残杀的程度很高（70%）。个体的总繁殖力估计为702240个卵。发现三种寄生虫，两种来自套腔的扁线虫（Phyllobothrium sp.和Nybelinia sp.）和一种来自胃的线虫（Anisakis simplex）。COI条形码证实了这一巨型标本的身份，即S.oualaniensis，在目前的标本和来自不同海洋的其他标本之间观察到的高度遗传差异（6.18–9.35%）表明，它可能是北印度洋的一个遗传上不同的谱系。目前的记录形成了这种巨型飞行乌贼最南端（北纬10°05′）的记录。
{"title":"Characterisation of an individual of the giant form of the purpleback flying squid Sthenoteuthis oualaniensis (Cephalopoda: Ommastriphidae) in the Arabian Sea and its biological descriptors","authors":"K. K. Sajikumar, T. M. Najmudeen, N. Ragesh, N. S. Jeena, Summaya Rahuman, K. T. S. Sunil, G. Sasikumar, Kolliyil Sunilkumar Mohamed","doi":"10.1080/13235818.2021.2003513","DOIUrl":"https://doi.org/10.1080/13235818.2021.2003513","url":null,"abstract":"ABSTRACT This paper describes a mated female of the giant form of purpleback flying squid Sthenoteuthis oualaniensis (545 mm dorsal mantle length and 5.46 kg body weight) caught in the Arabian Sea, with biological, morphological, and molecular descriptors. Based on the growth increments within statoliths, its age was found to be 203 days with a high growth rate of 2.68 mm DML/day. Its diet contained squids (72.3%) and fish (27.3%) with a high degree (70%) of cannibalism. The total fecundity of the individual was estimated as 702,240 eggs. Three species of parasites were found, two species of Platyhelminthes from the mantle cavity (Phyllobothrium sp. and Nybelinia sp.) and one of Nematoda from the stomach (Anisakis simplex). The COI barcode confirmed the identity of the giant form as S. oualaniensis, and the high genetic divergence (6.18–9.35%) that was observed between the current specimen and other forms from various oceans points to the probability that it might be a genetically distinct lineage from the northern Indian Ocean. The present record forms the southernmost (10°05′ N) record of the giant form of this flying squid.","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"41 1","pages":"275 - 284"},"PeriodicalIF":1.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49425192","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}
Pub Date : 2021-10-02DOI: 10.1080/13235818.2021.1991255
Nipu Kumar Das, B. Páll‐Gergely, F. Naggs, R. C. Preece, T. White, N. A. Aravind
ABSTRACT The type species of the assimineid genus Acmella W.T. Blanford, 1869 is Cyclostoma tersum Benson, 1853, originally described from ‘Musmai’ [Mawsmai], Meghalaya, Northeast India. No specimens from Benson’s type series can be traced, and contemporary shells collected from the type locality in museum collections are extremely worn. It has therefore been impossible to examine shell microsculpture, an important taxonomic character in the diagnosis of species of Assimineidae, using museum specimens. In order to provide better diagnostic characters for the genus Acmella, we redescribe and illustrate Acmella tersa from newly collected specimens, one of which is designated as the neotype. We also provide a list of all known species attributed to Acmella.
{"title":"Redescription of Acmella tersa (Benson, 1853), the type species of Acmella W.T. Blanford, 1869 (Gastropoda: Assimineidae), from Meghalaya, Northeast India","authors":"Nipu Kumar Das, B. Páll‐Gergely, F. Naggs, R. C. Preece, T. White, N. A. Aravind","doi":"10.1080/13235818.2021.1991255","DOIUrl":"https://doi.org/10.1080/13235818.2021.1991255","url":null,"abstract":"ABSTRACT The type species of the assimineid genus Acmella W.T. Blanford, 1869 is Cyclostoma tersum Benson, 1853, originally described from ‘Musmai’ [Mawsmai], Meghalaya, Northeast India. No specimens from Benson’s type series can be traced, and contemporary shells collected from the type locality in museum collections are extremely worn. It has therefore been impossible to examine shell microsculpture, an important taxonomic character in the diagnosis of species of Assimineidae, using museum specimens. In order to provide better diagnostic characters for the genus Acmella, we redescribe and illustrate Acmella tersa from newly collected specimens, one of which is designated as the neotype. We also provide a list of all known species attributed to Acmella.","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"41 1","pages":"324 - 331"},"PeriodicalIF":1.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46176828","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}
Pub Date : 2021-10-02DOI: 10.1080/13235818.2021.1984189
A. Sulikowska-Drozd, C. Hwang, B. Páll‐Gergely, Shu-Ping Wu
ABSTRACT Family Clausiliidae (door-snails), which includes oviparous, embryo-retaining and viviparous species, can be a model group for studies on the evolution of reproductive modes in land snails. Yet, for understanding of evolutionary drivers leading to repeated changes of reproductive strategy, the identification of life history traits in phylogenetic lineages and geographical regions is fundamental. In this paper, we identified reproductive modes of clausiliid species endemic to Taiwan: Changphaedusa horikawai, Formosana formosensis, F. swinhoei, and an undescribed new species Formosana sp. Observations were conducted under laboratory conditions. Among Formosana species, oviparity predominated but embryo-retention was also recorded. The size of eggs and egg clutches differed between studied taxa. In contrast, C. horikawai was viviparous and delivered neonates. Anatomical examination of the fresh material allowed for unique observation of a large podocyst in embryos kept in the genital tract. This flattened structure may enable respiration or nutrient transfer between an embryo and a parent. In the regularly sampled wild population from Dawulun (N. Taiwan), gravid individuals were collected between April and November. The number of embryos reached three to nine per gravid individual. None of the species reproduced by self-fertilisation. Results of our study may support implementing conservation measures for malacofauna of Taiwan.
{"title":"Giants of Taiwan – comparative analysis of life history traits in four land snail species Changphaedusa horikawai, Formosana swinhoei, F. formosensis, and Formosana sp. (Stylommatophora: Clausiliidae: Phaedusinae)","authors":"A. Sulikowska-Drozd, C. Hwang, B. Páll‐Gergely, Shu-Ping Wu","doi":"10.1080/13235818.2021.1984189","DOIUrl":"https://doi.org/10.1080/13235818.2021.1984189","url":null,"abstract":"ABSTRACT Family Clausiliidae (door-snails), which includes oviparous, embryo-retaining and viviparous species, can be a model group for studies on the evolution of reproductive modes in land snails. Yet, for understanding of evolutionary drivers leading to repeated changes of reproductive strategy, the identification of life history traits in phylogenetic lineages and geographical regions is fundamental. In this paper, we identified reproductive modes of clausiliid species endemic to Taiwan: Changphaedusa horikawai, Formosana formosensis, F. swinhoei, and an undescribed new species Formosana sp. Observations were conducted under laboratory conditions. Among Formosana species, oviparity predominated but embryo-retention was also recorded. The size of eggs and egg clutches differed between studied taxa. In contrast, C. horikawai was viviparous and delivered neonates. Anatomical examination of the fresh material allowed for unique observation of a large podocyst in embryos kept in the genital tract. This flattened structure may enable respiration or nutrient transfer between an embryo and a parent. In the regularly sampled wild population from Dawulun (N. Taiwan), gravid individuals were collected between April and November. The number of embryos reached three to nine per gravid individual. None of the species reproduced by self-fertilisation. Results of our study may support implementing conservation measures for malacofauna of Taiwan.","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"41 1","pages":"298 - 315"},"PeriodicalIF":1.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46172291","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}
Pub Date : 2021-10-02DOI: 10.1080/13235818.2021.2004574
Abdelmajid El Khayari, E. Rour
ABSTRACT This study investigates the reproduction of Otala tingitana (Paladilhe, 1875) snails collected from El Hajeb region (Morocco) after aestivation and reared in transparent containers under eight different combinations of air temperature, relative humidity (RH), and photoperiod [hours of light (L) and darkness (D)]. Biomass change was used to evaluate the growth of the snails. Mating, egg-laying, and hatching were monitored to assess reproduction rate in different artificial conditions. Animals that were reared under a combination of (20°C, 50% RH, 16L-8D) showed improved mating frequency, whereas the best breeding yield and reproduction rate were obtained with a combination of 20°C, 80% RH, and 16L-8D photoperiod. Except for one condition in which inhibition of laying was recorded (15°C, 50% RH, 16L-8D), O. tingitana snails showed high plasticity regarding the environmental factors tested. However, in all combinations used, none of the parameters was a limiting factor; instead, we suggest that the interaction between the three parameters modulates snail growth and reproduction. Overall, for the first time this study examined experimental evidence about the effect of environmental factors on the reproduction of Otala tingitana, thereby defining the optimal combination of temperature, humidity, and photoperiod for improved breeding of this species.
{"title":"Combined effects of air temperature, photoperiod and humidity on Otala tingitana snails’ breeding (Mollusca, Gastropoda, Helicidae)","authors":"Abdelmajid El Khayari, E. Rour","doi":"10.1080/13235818.2021.2004574","DOIUrl":"https://doi.org/10.1080/13235818.2021.2004574","url":null,"abstract":"ABSTRACT This study investigates the reproduction of Otala tingitana (Paladilhe, 1875) snails collected from El Hajeb region (Morocco) after aestivation and reared in transparent containers under eight different combinations of air temperature, relative humidity (RH), and photoperiod [hours of light (L) and darkness (D)]. Biomass change was used to evaluate the growth of the snails. Mating, egg-laying, and hatching were monitored to assess reproduction rate in different artificial conditions. Animals that were reared under a combination of (20°C, 50% RH, 16L-8D) showed improved mating frequency, whereas the best breeding yield and reproduction rate were obtained with a combination of 20°C, 80% RH, and 16L-8D photoperiod. Except for one condition in which inhibition of laying was recorded (15°C, 50% RH, 16L-8D), O. tingitana snails showed high plasticity regarding the environmental factors tested. However, in all combinations used, none of the parameters was a limiting factor; instead, we suggest that the interaction between the three parameters modulates snail growth and reproduction. Overall, for the first time this study examined experimental evidence about the effect of environmental factors on the reproduction of Otala tingitana, thereby defining the optimal combination of temperature, humidity, and photoperiod for improved breeding of this species.","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"41 1","pages":"316 - 323"},"PeriodicalIF":1.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43184222","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}
Pub Date : 2021-10-02DOI: 10.1080/13235818.2021.2003982
A. Ibrahim, H. A. Saleh, Khaled M. Zayed, M. Ghazy
ABSTRACT Schistosomiasis is considered a neglected disease, but it is the cause of many social and economic problems in many developing countries. The aim of the present study was to find an alternative molluscicide of botanical origin to decrease the spread of this disease. The investigation studied the effect of the methanolic extract of Colchicum ritchii flowers on Biomphalaria alexandrina snails, larvae of Schistosoma mansoni, and the freshwater cladoceran Daphnia magna. The preliminary phytochemical screening test confirmed the presence of tannins and saponins that might be responsible for cytotoxic effects. The methanolic extract had a molluscicidal activity on B. alexandrina snails with an LC50 of 35.1 mg L−1 after 24 h of exposure. The LC50 of D. magna after 24 h was 63.5 mg L−1. The extract also had a larvicidal activity and caused alterations in the haemocytes of B. alexandrina snails. Aggregations of both hyalinocytes and granulocytes were formed after exposure for 24 h to LC25. Both the mean number of micronuclei per slide and the olive tail moment of snails exposed to LC10 and LC25 of the extract were increased compared to control snails. In conclusion, C. ritchii extract potentially could be used as a molluscicide and larvicide.
{"title":"Colchicum Ritchii flower: a new molluscicidal plant for Biomphalaria alexandrina snails and the infective stages of Schistosoma mansoni","authors":"A. Ibrahim, H. A. Saleh, Khaled M. Zayed, M. Ghazy","doi":"10.1080/13235818.2021.2003982","DOIUrl":"https://doi.org/10.1080/13235818.2021.2003982","url":null,"abstract":"ABSTRACT Schistosomiasis is considered a neglected disease, but it is the cause of many social and economic problems in many developing countries. The aim of the present study was to find an alternative molluscicide of botanical origin to decrease the spread of this disease. The investigation studied the effect of the methanolic extract of Colchicum ritchii flowers on Biomphalaria alexandrina snails, larvae of Schistosoma mansoni, and the freshwater cladoceran Daphnia magna. The preliminary phytochemical screening test confirmed the presence of tannins and saponins that might be responsible for cytotoxic effects. The methanolic extract had a molluscicidal activity on B. alexandrina snails with an LC50 of 35.1 mg L−1 after 24 h of exposure. The LC50 of D. magna after 24 h was 63.5 mg L−1. The extract also had a larvicidal activity and caused alterations in the haemocytes of B. alexandrina snails. Aggregations of both hyalinocytes and granulocytes were formed after exposure for 24 h to LC25. Both the mean number of micronuclei per slide and the olive tail moment of snails exposed to LC10 and LC25 of the extract were increased compared to control snails. In conclusion, C. ritchii extract potentially could be used as a molluscicide and larvicide.","PeriodicalId":18857,"journal":{"name":"Molluscan Research","volume":"41 1","pages":"289 - 297"},"PeriodicalIF":1.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48796888","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}
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