Atypical reproduction in a syllid worm: the stolon of Syllis rosea (Annelida, Syllidae) takes care of its offspring

2020 ◽  
Vol 100 (2) ◽  
pp. 221-227
Author(s):  
Joachim Langeneck ◽  
Michela Del Pasqua ◽  
Margherita Licciano ◽  
Adriana Giangrande ◽  
Luigi Musco
Keyword(s):  
Parental Care ◽  
Sexual Reproduction ◽  
Reproductive Strategy ◽  
Reproductive Strategies ◽  
Congeneric Species ◽  
Reproduction Mode ◽  
Laboratory Rearing ◽  
Larval Stages ◽  
The Family ◽  
Reproductive Cycles

AbstractThe family Syllidae, aside from representing the most species-rich family in Annelida, is characterized by a number of sexual and asexual reproductive strategies. With the exception of a few viviparous species, the subfamily Syllinae is characterized by schizogamous reproduction with pelagic larval stages and without parental care. Laboratory rearing of ripe specimens of Syllis rosea showed a different reproductive strategy, hitherto unknown in this subfamily. While male stolons rapidly degenerated after fertilization, female ones released large eggs in a gelatinous cluster attached to the middle-posterior chaetigers. The gel mass progressively compacted as a cocoon wrapped by the stolon body; 7 days after the deposition the larvae hatched out from the cocoon at the metatrochophore stage and the female stolon died after a few days. After hatching the larvae remained associated to the stolon, and young specimens of S. rosea survived up to the 3-chaetiger stage. Until now cocoon brooding by the stolon has only been reported for some Autolytinae. The production of gelatinous egg masses and parental care are known in basally branching clades within Syllidae, suggesting that this reproduction mode might retain some ancestral features. The scarce knowledge about reproductive cycles in Syllinae does not allow clarification whether this strategy is unique for S. rosea, or it occurs in other congeneric species. Further research is needed to understand possible relationships between sexual reproduction and phylogeny, stolon morphology and its adaptation to parental care, and ultimately between reproductive strategies and ecology.

Twinning and the r/K Reproductive Strategy: A Critique of Rushton's Theory

1992 ◽  
Vol 41 (1) ◽  
pp. 73-83 ◽  
Author(s):  
G. Allen ◽  
A.W. Eriksson ◽  
J. Fellman ◽  
P. Parisi ◽  
S.G. Vandenberg
Keyword(s):  
Environmental Factors ◽  
Population Growth ◽  
Parental Care ◽  
Ethnic Groups ◽  
Ethnic Differences ◽  
Reproductive Strategy ◽  
Reproductive Strategies ◽  
Human Populations ◽  
Efficient Utilization ◽  
Mode Of Reproduction

AbstractThe theory of r selection, favoring population growth, as opposed to K selection, favoring more efficient utilization of resources, has in recent years been applied by Rushton to contrast human ethnic groups in terms of their r/K reproductive strategies, suggesting the existence of a continuum from r groups, producing many offspring but providing little parental care, to K groups, producing few offspring but providing much parental care. Rushton's theory, which is largely based on ethnic differences in twinning rates, is here critically examined. It is pointed out that twinning rate differences are not necessarily genetic in origin since various environmental factors clearly play a role, and also that twinning, as a mode of reproduction, is not necessarily an r strategy, considering the high prenatal and perinatal selection to which it has been, and still is, associated. Moreover, Rushton misinterprets a number of relevant aspects related to the biology of twinning. The claim that ethnic differences in twinning rates provide evidence for an r/K typology in human populations with respect to reproductive strategies does not appear to be warranted.

Larval development of Metapenaeopsis barbata (de Haan, 1844) (Crustacea: Decapoda: Penaeidae)

1997 ◽  
Vol 48 (5) ◽  
pp. 401 ◽  
Author(s):  
Jesse D. Ronquillo ◽  
Toshio Saisho
Keyword(s):  
Morphological Characteristics ◽  
Larval Feeding ◽  
Feeding Apparatus ◽  
Filter Feeder ◽  
Closely Related Species ◽  
Larval Stages ◽  
Chaetoceros Gracilis ◽  
The Family ◽  
Gravid Females ◽  
Natural Means

Gravid females of Metapenaeopsis barbata spawned in the laboratory by natural means and the larvae were reared from hatching to postlarval stage at 27·0–29·8˚C and 33·5–34·5 g kg -1 salinity. The larvae metamorphosed into first postlarvae, with a survival rate of up to 98·4%, after about 10 days following hatching and subsistence on only an algal diet of Tetraselmis tetrathele and Chaetoceros gracilis. Six naupliar stages, three protozoeal stages, three mysis stages and the first postlarval stage are described and illustrated. On the basis of morphological characteristics, larval stages of M. barbata can be distinguished from similar stages of closely related species in the family Penaeidae. As inferred from the morphology of the larval feeding apparatus, M. barbata is still a filter-feeder even at the first postlarval stage.

New species of the genus Plonaphacarus (Oribatida, Steganacaridae) from China

2021 ◽  
Author(s):  
Dong Liu ◽  
Min Huang
Keyword(s):  
New Species ◽  
Congeneric Species ◽  
Anterior Border ◽  
The Family ◽  
Two New Species

Two new species belonging to the family Steganacaridae are described from Oriental part of China: Plonaphacarus luxiensis sp. nov. differs from Plonaphacarus concavus Liu, Wu & Chen, 2011 by the long and stout interlamellar and lamellar setae, lateral prodorsal carinae absent, exobothridial setae vestigial, anterodorsal part of notogaster not concave dorsally, notogastral setae c1 and anal setae short and spiniform, setae c1 positioned close to anterior border of notogaster and setae d on femora I distanced to distal end of segment; Plonaphacarus hailingensis sp. nov. differs from congeneric species by the presence of heterotrichy of notogastral setae, in which setae c1, c2 and c3 long and flagellate distally, prodorsum with median crista and posterior furrows, sensilli long and setiform, and rostral setae short, spiniform and semi-erect. A key to all known species of Plonaphacarus from China are provided to facilitate identification of this group.

A three year study of seasonal dynamics of a zoobenthos community in a eutrophic lake

Nematology ◽  
2004 ◽  
Vol 6 (5) ◽  
pp. 655-669 ◽  
Author(s):  
Iris Michiels ◽  
Walter Traunspurger
Keyword(s):  
Seasonal Dynamics ◽  
Reproductive Strategies ◽  
Seasonal Pattern ◽  
Nematode Species ◽  
Eutrophic Lake ◽  
Nematode Community ◽  
Benthic Biomass ◽  
The Family ◽  
Feeding Type ◽  
Meiofauna Community

AbstractThe meiofauna community in the eutrophic Lake Obersee was investigated, with special emphasis on nematodes, from March 2001 to December 2003. Meiobenthos showed a stable annual and seasonal pattern with oligochaetes contributing most to benthic biomass and nematodes to benthic abundance. With 152 nematode species, Lake Obersee is the most nematode species-rich lentic habitat described so far. The nematode community was dominated by the family Monhysteridae. Bacterial feeders were the most abundant feeding type; omnivorous nematodes contributed most to total nematode biomass. Reproduction occurred throughout the year, with most species reproducing parthenogenetically. No seasonal pattern in reproductive strategies was found.

Philometra barbata n. sp. (Nematoda: Philometridae) from the red mullet Mullus barbatus (Perciformes, Mullidae) off Tunisia

2018 ◽  
Vol 63 (4) ◽  
pp. 766-771 ◽  
Author(s):  
Nessrine Ghanmi ◽  
David González-Solís ◽  
Lamia Gargouri
Keyword(s):  
New Species ◽  
Mediterranean Sea ◽  
Body Length ◽  
Nematode Species ◽  
The Body ◽  
Nominal Species ◽  
Congeneric Species ◽  
Red Mullet ◽  
Mullus Barbatus ◽  
The Family

Abstract Helminthological examinations of the red mullet Mullus barbatus (Linnaeus) (Mullidae) from the Gulf of Hammamet, off Tunisia, revealed the presence of one undescribed gonad-infecting nematode species, Philometra barbata n. sp. (Philometridae). The new species as other congeneric species is mainly characterized by the shape of the caudal mound, the distribution of the caudal papillae and the shape of the gubernaculum with the presence of a dorsal protuberance consisting of two dorsolateral lamellar parts separated from each other by a smooth median field in the male. The new species differs from its gonadinfecting congeners in the body length of male, the length of spicules and gubernaculum. This is the second nominal species of Philometra reported from fishes of the family Mullidae and the 14th from the Mediterranean Sea.

scholarly journals Influence of breeding strategy on genetic diversity of individuals

2021 ◽  
pp. 1168-1174
Author(s):  
A.A. Poroshina ◽  
◽  
D.Yu. Sherbakov ◽  
Keyword(s):  
Genetic Diversity ◽  
Computer Simulation ◽  
Molecular Evolution ◽  
Microsatellite Markers ◽  
Simulation Model ◽  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Reproductive Strategy ◽  
Breeding Strategy ◽  
Computer Simulation Model

Abstract. Using a computer simulation model, we tried to investigate how the transition from sexual reproduction to asexual reproduction will affect the population of diploid organisms with a neutral character of molecular evolution. At the same time, special attention was paid to the specificity of microsatellite markers. In this paper, we develop fast and inexpensive methods for assessing the changes in populations that occur with a change in reproductive strategy.

scholarly journals The principle of self-determination in the family law through history and today

2004 ◽  
pp. 159-178
Author(s):  
Gordana Kovacek-Stanic
Keyword(s):  
Parental Care ◽  
Family Law ◽  
Family Relations ◽  
Historical Context ◽  
Civil Code ◽  
Self Determination ◽  
200Th Anniversary ◽  
Parents And Children ◽  
The Family ◽  
The Moment

In the jubilee year 2004, Serbia marks the 200th anniversary of The First Serbian Uprising, structuring of modern Serbian state and its legal system comparatively speaking, France marks the 200th anniversary of passing the French Civil Code, one of the most significant civil codifications in the 19th century. It was an occasion to study certain institutions of family law through history and today. The used approach is modern, we studied the ways how the principle of self-determination influenced the family-legal solutions today, and we investigated if one could talk about the effect of this principle in the historical sense, too. The principle of self-determination implies the possibility for the subjects of family-legal relations to arrange their own relations themselves ? both the partner and parent relations. However, this principle undergoes significant limitations in the family law because the family relations are personal relations by character, as well as because of the need to protect the weaker participant, both the weaker partner or a child who needs protection stemming from his/her very status. Within marriage law, the principle of self-determination of the spouses (extramarital partners) is, among other things, made concrete through the possibility for an agreement about the effects of marriage (extramarital union), then through the possibility of agreed divorce, while the procedure of mediation in the marriage litigation contributes to the realization of the mentioned principle. As for the effects of marriage (extramarital union), the paper particularly discusses property relations, that is the marriage property contract, because it is at the moment a current issue in our domestic law. Within the relations between parents and children, the concretization of the principle of self-determination in parental care is significant, particularly in the situations when the relations between the parents were disturbed and resulted in a separation or a divorce with the joint parental care (application of the parental right). All institutions are analyzed in the positive law, in the historical context (solutions from the Serbian Civil Code the former Hungarian Law), and viewed comparatively in the European legal systems of the east and west European countries.

scholarly journals SUBJECTS OF ADMINISTRATIVE AND LEGAL SUPPORT IDENTIFICATION OF CHILDREN SEPARATED WITH FAMILY IN UKRAINE

2020 ◽  
pp. 205-210
Author(s):  
А. М. Мамульчик
Keyword(s):  
Parental Care ◽  
Public Administration ◽  
Local Governments ◽  
Legal Status ◽  
Refugee Status ◽  
Public Authorities ◽  
Her Family ◽  
The Family ◽  
Additional Protection ◽  
The Status

The relevance of the article is that the granting of special status «child divorced from the family» in the Ukrainian legislation includes three aspects: 1) identification of a person who is a child separated from the family; 2) granting the status of «child deprived of parental care»; 3) it is possible to grant the status of “refugee” or “person in need of additional protection”, as any person recognized as a child divorced from a family is recognized as a child deprived of parental care and can apply for asylum in Ukraine (and receive refugee status or a person in need of additional protection). Each of the identified aspects of the above status is the responsibility of certain public authorities, ie public administration entities, which are endowed with the appropriate powers. The purpose of the article is to identify the subjects of administrative and legal support for the identification of children separated from their families, ie the subjects of public administration, which are empowered to identify such children in Ukraine. It was found that in fact, the identification of a child separated from the family at the present stage in Ukraine does not belong to the responsibilities of public administration, but is the responsibility of the child who was forced to leave the country of origin or residence and arrived in the territory of Ukraine unaccompanied by a family member or persons determined by law/custom who are responsible for such a person, or who were left unaccompanied after arriving on the territory of Ukraine, or its legal representatives. In our opinion, the absence in the legal acts that determine the legal status of public administration entities, whose activities include the identification of children separated from their families, their obligation to identify such children is a shortcoming of administrative and legal support for child status. , separated from her family, in Ukraine. It is determined that the subjects of public administration, which have the authority to identify children separated from their families, include the State Border Guard Service of Ukraine, executive authorities, local governments, the National Police of Ukraine, the Prosecutor’s Office of Ukraine.

scholarly journals Debating phylogenetic relationships of the scleractinian Psammocora: molecular and morphological evidences

2007 ◽  
Vol 76 (1) ◽  
pp. 35-54 ◽  
Author(s):  
Francesca Benzoni ◽  
Fabrizio Stefani ◽  
Jaroslaw Stolarski ◽  
Michel Pichon ◽  
Guillaume Mitta ◽  
...  
Keyword(s):  
Molecular Phylogeny ◽  
Phylogenetic Relationships ◽  
Molecular Data ◽  
Genetic Distances ◽  
The Other ◽  
Congeneric Species ◽  
Genetic Affinity ◽  
Phylogenetic Structure ◽  
Skeletal Structures ◽  
The Family

The phylogenetic relationships of the scleractinian genus Psammocora with the other genera traditionally included in the family Siderastreidae and some Fungiidae are assessed based on combined skeletal and molecular data. P. explanulata differs from the other examined congeneric species (P. contigua, P. digitata, P. nierstraszi , P. profundacella, P. superficialis, and P. stellata) in possessing interstomatous septa between adult corallites, costae, and in having continuous buttress-like structures joining septal faces (i.e., fulturae) which typically occur in fungiids. These characters are shared with Coscinaraea wellsi but not with the remainder of the examined siderastreids (the congeneric C. columna, and Anomastraea irregularis, Horastrea indica, Pseudosiderastrea tayamai, Siderastrea savignyana) whose septa are interconnected by typical synapticulae. Most of the examined species form septa with distinct transverse groups of centers of calcification, a biomineralization pattern typical of the Robusta clade. The observations on skeletal structures corroborate the results of the ITS2 and 5.8S molecular phylogeny. C. wellsi and P. explanulata are phylogenetically very close to each other and show closer genetic affinity with the examined Fungiidae (Halomitra pileus, Herpolitha limax, Fungia paumotensis, and Podabacia crustacea) than with the other species in the genera Psammocora and Coscinaraea, or with any other siderastreid. Our results show that neither Psammocora nor Coscinaraea are monophyletic genera. The high genetic distances between the species of Siderastreidae, especially between Pseudosiderastrea tayamai and Siderastrea savignyana on one side and the other genera on the other, suggest a deep divergence in the phylogenetic structure of the family.

scholarly journals Reproductive Strategies of the Seagrass Zostera japonica Under Different Geographic Conditions in Northern China

2020 ◽  
Vol 7 ◽  
Author(s):  
Shidong Yue ◽  
Xiaomei Zhang ◽  
Shaochun Xu ◽  
Yu Zhang ◽  
Peng Zhao ◽  
...  
Keyword(s):  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Reproductive Strategies ◽  
Geographic Location ◽  
Dry Weight ◽  
Northern China ◽  
Shoot Density ◽  
Zostera Japonica ◽  
Sexual And Asexual Reproduction ◽  
Density And Biomass

Seagrasses form a unique group of submerged marine angiosperms capable of both sexual and asexual reproduction. The amounts of sexual and asexual reproduction differ within some species relying on geographic location and environmental factors. Here, we studied the reproductive strategies of different geographic Zostera japonica populations, S1 and S2 at Swan Lake lagoon (SLL), and H1 and H2 at Huiquan Bay (HQB), in northern China. The duration of flowering at SLL was longer than at HQB, whereas flowering initiation at HQB occurred earlier than at SLL. In addition, the timing of seed maturation at HQB occurred earlier than at SLL. The allocation to sexual reproduction at SLL was greater than at HQB. The maximum potential seed production was greatest at S1 (22228.52 ± 8832.46 seeds ⋅ m–2), followed by S2 (21630.34 ± 9378.67 seeds ⋅ m–2), H2 (7459.60 ± 1779.33 seeds ⋅ m–2), and H1 (2821.05 ± 1280.57 seeds ⋅ m–2). The seasonal changes in total shoot density and biomass were small at HQB. There was a relatively large number of overwintering shoots at HQB because of the higher average temperature during winter. The allocation to sexual reproduction was lower than at SLL, and no seedlings were observed at HQB during our study. Thus, the population of Z. japonica at HQB was maintained by asexual reproduction. Compared with HQB, the biomass of overwintering shoots at SLL was less than 30 g dry weight ⋅ m–2. The Z. japonica at SLL relied on asexual and sexual reproduction to maintain the population. The results show the necessity of understanding local reproductive strategies before starting restoration and management projects. The study provides fundamental information and guidance for the conservation and restoration of seagrass beds.

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