Description of the second species of Synhalcurias Carlgren, 1914, Synhalcurias kahakui sp. nov. (Actiniaria: Actinernidae) with redescription of S. elegans (Wassilieff, 1908)

Zootaxa ◽  
2021 ◽  
Vol 5048 (4) ◽  
pp. 561-574
Author(s):  
TAKATO IZUMI ◽  
KENSUKE YANAGI
Keyword(s):  
New Species ◽  
Sea Anemone ◽  
Sea Anemones ◽  
Oral Disc ◽  
Mesenterial Filaments

We describe a new sea anemone species, Synhalcurias kahakui sp. nov., from specimens collected off Otouto-jima and Amami-oshima islands in July 2016 and May 2019. respectively. These sea anemones were identified as belonging to family Actinernidae due to their many endocoelic perfect mesenteries and identified as belonging to the genus Synhalcurias Carlgren, 1914 because they have an oral disc without any developed lobes. Though this genus presently accommodates only one species, Synhalcurias elegans (Wassilieff, 1908), our specimens are smaller than the aforementioned species, have fewer mesenteries, lack nematocyst batteries on the column, and have two types of microbasic p-mastigophores on the mesenterial filaments. These specimens are described as Synhalcurias kahakui sp. nov. In view of the new species, the diagnosis of genus Synhalcurias is revised. In addition, we redescribe S. elegans based on newly specimens collected from Japan.  

A new vermiform sea anemone (Anthozoa: Actiniaria) from Argentina: Harenactis argentina sp. nov.

Zootaxa ◽  
2011 ◽  
Vol 3027 (1) ◽  
pp. 9 ◽  
Author(s):  
DANIEL LAURETTA ◽  
ESTEFANÍA RODRÍGUEZ ◽  
PABLO E. PENCHASZADEH
Keyword(s):  
New Species ◽  
Southern Hemisphere ◽  
First Record ◽  
Sea Anemone ◽  
Soft Bottom ◽  
Sea Anemones ◽  
A New Species

During 2007, 2008, and 2010, 23 specimens of an undescribed vermiform sea anemone were collected on Punta Pardelas and Fracaso Beach (Península Valdés, Argentina). The specimens have longitudinal rows of cinclides distally, all mesenteries perfect, tentacles hexamerously arranged without acrospheres, column not divisible into regions, no marginal sphincter and no conchula. We describe these specimens as a new species within the genus Harenactis (family Haloclavidae). Harenactis argentina sp. nov. is the second species of Harenactis; it represents the first record of this genus in the southern hemisphere and the first record of a soft bottom-dwelling sea anemone in the Argentine continental zone. Furthermore, we discuss the familial placement and relationships of the genus Harenactis and other athenarian sea anemones.

The behavioural physiology of the swimming sea anemone Boloceroides mcmurrichi

1982 ◽  
Vol 216 (1204) ◽  
pp. 315-334 ◽  
Keyword(s):  
Chemical Substance ◽  
Sea Anemone ◽  
Local Autonomy ◽  
Sea Anemones ◽  
Oral Disc ◽  
Electrophysiological Studies ◽  
Mode Of Life ◽  
Electrical Stimuli ◽  
High Degree ◽  
Pedal Disc

The Indo-Pacific sea anemone, Boloceroides mcmurrichi , swims by coordinated lashing of tentacles and can cast off tentacles by autotomy. A predator of Boloceroides , the aeolid Berghia major , causes the anemone to detach its pedal disc and swim away after brief contact with the tentacles, a response apparently due to a chemical substance in the aeolid. Berghia generally attacks the anemone by making a lunge into the midst of the tentacles. Any tentacles seized by the aeolid autotomize, so that the anemone is not held by the aeolid when it begins to swim. Thus these two adaptations, swimming and autotomy, while not preventing predation, keep it to levels easily countered by regeneration. In electrophysiological studies on Boloceroides , the pulses assocated with the conduction systems in other anemones (NN, SS1 and SS2) were not detected. The following identifiable pulses were consistently recorded: (i) tentacle burst pulses (TBP) from isolated and intact tentacles correlated with tentacle flexions; (ii) flexion trigger pulses (FTP) recorded from oral disc and intact tentacles correlated with coordinated tentacle flexions; (iii) swimming trigger pulses (STP) recorded from the pedal disc, preceding bouts of swimming in response to the aeolid, B. major, and to mechanical and electrical stimuli; (iv) swimming arrest pulses (SAP) recorded from the pedal disc and appearing towards the end of bouts of swimming and followed almost at once by their cessation; (v) through-conduction pulses (TCP) recorded from the oral disc as a result of electrical stimuli on the column. The contrast between these pulses and those in other sea anemones probably reflects differences in the structure and mode of life of the anemone in question. A high degree of local autonomy of conduction systems is indicated. The pulses so far detected in Boloceroides reflect the behavioural capacities and the special adaptations of this atypical anemone, but pulses associated with overall coordination remain to be discovered.

Actinia ebhayiensis sp. nov., a new species of sea anemone (Anthozoa: Actiniaria: Actiniidae) from South Africa

2011 ◽  
Vol 92 (5) ◽  
pp. 885-894 ◽  
Author(s):  
Renata Schama ◽  
Michela Mitchell ◽  
Antonio Mateo Solé-Cava
Keyword(s):  
South Africa ◽  
New Species ◽  
Type Species ◽  
Genetic Data ◽  
Allozyme Data ◽  
Oral Disc ◽  
Pink Colour ◽  
A New Species ◽  
Pedal Disc ◽  
Mesenterial Filaments

In this work we describe Actinia ebhayiensis sp. nov. from South Africa. The species is externally similar to the type species of the genus, Actinia equina, from which it can be distinguished by nematocyst and allozyme data. Actinia ebhayiensis has a smooth, red column, with well-delimited parapet leading to a deep fosse where conspicuous blue acrorhagi can be found. Tentacles and oral disc are crimson red, and the pedal disc has a lighter pink colour. The microbasic p-mastigophores and b-mastigophores of the mesenterial filaments of the new species are significantly smaller than those of A. equina. Actinia ebhayiensis can also be clearly distinguished from other species of the genus in nematocyst measurements, genetic data and muscle morphology.

Aulactinia sinensis, a new species of sea anemone (Cnidaria: Anthozoa: Actiniaria) from Yellow Sea

Zootaxa ◽  
2012 ◽  
Vol 3476 (1) ◽  
pp. 62
Author(s):  
YANG LI ◽  
RUI-YU LIU
Keyword(s):  
New Species ◽  
Yellow Sea ◽  
Intertidal Zone ◽  
Sea Anemone ◽  
A New Species ◽  
Mesenterial Filaments

Aulactinia sinensis, a new species of sea anemone collected from the intertidal zone of Qingdao, Yellow Sea, is describedand illustrated. This species is elongated, becoming plump distally, has circumscribed sphincter, and with 48 vertical rowsof verrucae in upper column, 48 pairs of mesenteries and 96 short tentacles. It is similar in shape to A. capitata Agassizin Verrill, 1864, but distinguished by its smaller basitrichs in tentacles and larger microbasic p-mastigophores in actinopharynx and mesenterial filaments.

Gametogenesis and the reproductive cycle in the deep-sea anemone Paracalliactis stephensoni (Cnidaria: Actiniaria)

1990 ◽  
Vol 70 (1) ◽  
pp. 163-172 ◽  
Author(s):  
Michel Praet-Van
Keyword(s):  
Organic Matter ◽  
Shallow Water ◽  
Deep Sea ◽  
Phytoplankton Bloom ◽  
Sea Anemone ◽  
Bay Of Biscay ◽  
Sea Anemones ◽  
Spring Phytoplankton Bloom ◽  
Sea Floor ◽  
Ultrastructural Investigation

This ultrastructural investigation of gametogenesis in a deep-sea anemone of the Bay of Biscay trawled around 2000 m depth, contributes to the knowledge of biology and strategy of reproduction of deep-sea benthos.This sea anemone is dioecious. The sperm appears very similar to those of shallow water sea anemones of the genus, Calliactis. The ultrastructural investigation of oogenesis allows the characteristics of the stages of previtellogenesis and vitellogenesis to be defined. The latter begins with a period of lipogenesis correlated with the formation of a trophonema. Mature oocytes measure up to 180 (im in diameter. Study of spermatogenesis and oogenesis reveals that spawning occurs in April/May. In males, the main area of testicular cysts, full of sperm, reaches maximal development from March to May and, in females, the percentage of mature oocytes decreases from 33% in April to 1% in May.Spawning may be induced by the advent in the deep-sea of the products of the spring phytoplankton bloom. This period of spawning, during the increased deposition of organic matter to the deep-sea floor, may be an advantageous strategy for early development of Paracalliactis.

scholarly journals Anthopleura mariscali, a new species of sea anemone (Cnidaria: Anthozoa: Actiniaria) from the Gal pagos Islands

Zootaxa ◽  
2004 ◽  
Vol 416 (1) ◽  
pp. 1 ◽  
Author(s):  
MARYMEGAN DALY ◽  
DAPHNE G. FAUTIN
Keyword(s):  
New Species ◽  
Intertidal Zone ◽  
Sea Anemone ◽  
Oral Surface ◽  
A New Species

Anthopleura mariscali, a new species of sea anemone (Actiniaria) known only from the intertidal zone of islands in the Gal pagos Archipelago, is described and illustrated. The column of a member of Anthopleura mariscali is orange to pink, becoming darker distally, and has prominent endocoelic marginal projections, each of which bears an acrorhagus on the oral surface and several verrucae on the adoral surface. Distally, the projections are typically frosted with opaque white patches. Living firmly adherent to the substratum in cracks and crevices, the animal is inconspicuous in life.

The Behaviour and Neuromuscular System of Gonactinia Prolifera, A Swimming Sea-Anemone

1971 ◽  
Vol 55 (3) ◽  
pp. 611-640
Author(s):  
ELAINE A. ROBSON
Keyword(s):  
Electrical Stimulation ◽  
Mechanical Stimulation ◽  
Motor Units ◽  
Nerve Cells ◽  
Sea Anemone ◽  
Neuromuscular System ◽  
Sea Anemones ◽  
Nerve Net ◽  
Local Contraction ◽  
Electric Shocks

1. In Gonactinia well-developed ectodermal muscle and nerve-net extend over the column and crown and play an important part in the anemone's behaviour. 2. Common sequences of behaviour are described. Feeding is a series of reflex contractions of different muscles by means of which plankton is caught and swallowed. Walking, in the form of brief looping steps, differs markedly in that it continues after interruptions. Anemones also swim with rapid tentacle strokes after contact with certain nudibranch molluscs, strong mechanical disturbance or electrical stimulation. 3. Swimming is attributed to temporary excitation of a diffuse ectodermal pacemaker possibly situated in the upper column. 4. From the results of electrical and mechanical stimulation it is concluded that the endodermal neuromuscular system resembles that of other anemones but that the properties of the ectodermal neuromuscular system require a new explanation. The size and spread of responses to electric shocks vary with intensity, latency is variable and there is a tendency to after-discharge. There is precise radial localization, for example touching a tentacle or the column causes it to bend towards or away from the stimulus. 5. A model to explain these and other features includes multipolar nerve cells closely linked to the nerve-net which would act as intermediate motor units, causing local contraction of the ectodermal muscle. This scheme can be applied to other swimming anemones but there is no evidence that it holds for sea anemones generally.

scholarly journals The Influence of Symbiont Diversity on the Functional Biology of a Model Sea Anemone

2021 ◽  
Author(s):  
◽  
Dorota Ewa Starzak
Keyword(s):  
Coral Reefs ◽  
Host Cell ◽  
Metabolic Cost ◽  
Global Scale ◽  
Sea Anemone ◽  
Host Tissue ◽  
Sea Anemones ◽  
Dominant Type ◽  
Symbiodinium Type ◽  
Symbiont Type

<p>Cnidarian–dinoflagellate symbioses, particularly those between anthozoans and dinoflagellates of the genus Symbiodinium (commonly referred to as zooxanthellae) are widespread in the marine environment. They are responsible for the formation of coral reefs and are thus of great ecological importance. In recent years there has been an increase in the frequency and severity of episodes of coral bleaching resulting in degradation and mortality of coral reefs on a global scale. In order to gain a deeper understanding of how corals can adapt to changing environmental conditions, the effect that symbiont type has on the persistence and physiology of an association needs to be ascertained. The aim of this research was to determine how different symbiont types affect the nutritional biology and intracellular physiology of the symbiosis when in association with the sea anemone Aiptasia pulchella. The specific objectives of the study were to; (1) determine whether different symbiont types are equally as adept at supporting the energetic demands of the same host; (2) determine if internal pH (pHi) is a reflection of symbiont type and whether the optimal pH for photosynthesis coincides with the host cell pHi; and (3) test the influence of Symbiodinium type on host tissue glycerol and glucose pools. In order to answer these questions, aposymbiotic (i.e. symbiont-free) sea anemones were infected with different Symbiodinium types and the relationship between symbiont type, photosynthetic performance and autotrophic potential was tested. A range of ‘normal’ and novel cnidarian–dinoflagellate symbioses was also used to measure host cell pHi and to determine the optimal pHi of isolated intact symbiosomes (i.e. the vacuoles that house the symbionts), as well as to compare the amounts of free glycerol and glucose (metabolites) present in the host tissues. Different host-symbiont combinations were found to have different photosynthetic and respiratory attributes. Earlier onset of full autotrophy (i.e. when all metabolic carbon demands of the symbiosis were met by photosynthesis) and higher CZAR values (i.e. the contribution of zooxanthellae to animal respiration) were demonstrated by symbioses hosting Symbiodinium B1 both from the original (homologous) and different (heterologous) host. The study showed that Symbiodinium types differ in their pH optima and that the optimal pHi for photosynthesis does not always match the actual measured pHi. Symbiont type was also shown to have an effect on host tissue glycerol and glucose pools, with the associations harbouring the homologous Symbiodinium B1 attaining the highest concentrations of both metabolites. Findings from this study suggest that corals may be able to maintain an association with a range of Symbiodinium types, and hence potentially switch as a consequence of bleaching. The new symbiont type may not be as nutritionally advantageous as the original type however, which could have implications for the growth and survivorship of the coral, unless it is able to supplement its carbon demands heterotrophically. The rapid proliferation of some of the heterologous Symbiodinium types (e.g. Symbiodinium E2) inside the host indicates that, after bleaching, there is potential for fast symbiont establishment. The reduced carbon contribution of these heterologous symbionts may not be a major concern should the coral be able to reinstate the more nutritionally advantageous symbiont as the dominant type during bleaching recovery. Finally, the rapid proliferation demonstrated by the heterologous Symbiodinium types and the associated metabolic cost to the host, could be an indication of the opportunistic nature of some of these types and may indicate a shift towards parasitism. It is imperative to extend this type of work to corals in the field to determine how these associations behave in nature. Also, in order to get a clearer picture of the diversity in symbiosis physiology, a wider range of Symbiodinium types needs to be investigated.</p>

scholarly journals Phylogenetic relationships among the clownfish-hosting sea anemones

2019 ◽  
Author(s):  
Benjamin M. Titus ◽  
Charlotte Benedict ◽  
Robert Laroche ◽  
Luciana C. Gusmão ◽  
Vanessa Van Deusen ◽  
...  
Keyword(s):  
Phylogenetic Reconstruction ◽  
Taxonomic Revision ◽  
Sea Anemone ◽  
Coral Triangle ◽  
Sea Anemones ◽  
Ecological Processes ◽  
Holistic Understanding ◽  
The Family ◽  
Genus 2 ◽  
Insight Into

AbstractThe clownfish-sea anemone symbiosis has been a model system for understanding fundamental evolutionary and ecological processes. However, our evolutionary understanding of this symbiosis comes entirely from studies of clownfishes. A holistic understanding of a model mutualism requires systematic, biogeographic, and phylogenetic insight into both partners. Here, we conduct the largest phylogenetic analysis of sea anemones (Order Actiniaria) to date, with a focus on expanding the biogeographic and taxonomic sampling of the 10 nominal clownfish-hosting species. Using a combination of mtDNA and nuDNA loci we test 1) the monophyly of each clownfish-hosting family and genus, 2) the current anemone taxonomy that suggests symbioses with clownfishes evolved multiple times within Actiniaria, and 3) whether, like the clownfishes, there is evidence that host anemones have a Coral Triangle biogeographic origin. Our phylogenetic reconstruction demonstrates widespread poly-and para-phyly at the family and genus level, particularly within the family Stichodactylidae and genus Sticodactyla, and suggests that symbioses with clownfishes evolved minimally three times within sea anemones. We further recover evidence for a Tethyan biogeographic origin for some clades. Our data provide the first evidence that clownfish and some sea anemone hosts have different biogeographic origins, and that there may be cryptic species of host anemones. Finally, our findings reflect the need for a major taxonomic revision of the clownfish-hosting sea anemones.

scholarly journals Identification of microsatellite loci in sea anemones Aulactinia stella and Cribrinopsis albopunctata (family Actiniidae)

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 232
Author(s):  
Ekaterina S. Bocharova ◽  
Alexey A. Sergeev ◽  
Aleksandr A. Volkov
Keyword(s):  
Population Genetics ◽  
Microsatellite Loci ◽  
Sea Anemone ◽  
Sea Anemones ◽  
Polymorphic Loci ◽  
Dna Libraries

From the DNA libraries enriched by the repeat motifs (AAAC)6, (AATC)6, (ACAG)6, (ACCT)6, (ACTC)6, ACTG)6, (AAAT)8, (AACT)8, (AAGT)8, (AGAT)8, for two viviparous sea anemones Aulactinia stella and Cribrinopsis albopunctata, 41 primer pairs were developed. These primer pairs resulted in the identification of 41 candidate microsatellite loci in either A. stella or C. albopunctata. Polymorphic loci were identified in both sea anemone species for 13 of the primer pairs and can be applicable for population genetics researches.

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