Clava multicornis

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Clava multicornis
Clava multicornis (from Allman, 1871).png
Male colony painted by G. J. Allman
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Hydrozoa
Order: Anthoathecata
Family: Hydractiniidae
Genus: Clava
Gmelin, 1788
Species:
C. multicornis
Binomial name
Clava multicornis
Forsskål, 1775

Clava is a monotypic genus of hydrozoans in the family Hydractiniidae. It contains only one accepted species, Clava multicornis. Other names synonymous with Clava multicornis include Clava cornea, Clava diffusa, Clava leptostyla, Clava nodosa, Clava parasitica, Clava squamata, Coryne squamata, Hydra multicornis, and Hydra squamata. [1] The larvae form of the species has a well developed nervous system compared to its small size. [2] The adult form is also advanced due to its ability to stay dormant during unfavorable periods. [3]

Contents

Anatomy

The larval form (planula) and adult form show two different body plans. The planula is a small, free-living larva, and is diploblastic with two layers: the endoderm and ectoderm with an additional mesoglea. The ectoderm thickness decreases from the anterior to posterior poles. Further, the ectoderm has mucous gland cells for secretory purposes, support, and sense along with cnidocytes with nematocysts in the posterior end. [2] The planula remain free-living for a short time, after which they settle onto hard substrate and then complete metamorphosis to become its adult form. [4] During metamorphosis, the species destroys most of its endoderm and ectoderm tissues as it undergoes a massive reorganization of its body. [5] In this form it stays attached to a substrate as a polyp. Features on the polyp include a mouth and tentacles. [4]

Nervous system

The planulae demonstrates cephalization with concentration of neurons and sensory cells in a dome shape at the anterior end. These neurons vary in types and function. [2] These sensory cells may include photoreceptors. [6] Additionally, it is believed that these planulae crawl by secretion of mucous gland cells which are secreted using neurons. [2] During metamorphosis, these neurons move within the organism. This is demonstrated in screening of GLWamide-immunoreactive neurons and RFamide-immunoreactive neurons. GLWamide-immunoreactive neurons display as neurotransmitters in cnidarian organisms. [2] These exist specifically in the polyp form of C. multicornis in the hypostome near the mouth. These will move along the body either upwards above the hypostome or downwards into the column of the polyp. [4] RFamide-immunoreactive neurons demonstrate neurons used for sensory purposes. C. multicornis have less of these neurons than the GLWamide-immnoreactive neurons. [2] These exist in the adult polyp form in the tentacles. These move along the tentacles and into the column of the polyp. [4]

GLWamide-immunoreactive neurons and RFamide-immunoreactive neurons can be affected by treatment of retinoic acid (RA) and Citral. RA prevents sensory cells to differentiate between GLWamide-immunoreactive and RFamide-immunoreactive neurons. This leads to the inability to react to light. Citral causes the embryos of C. multicornis to be shorter and unable to move. This is from a reduction in GLWamide-immunoreactive and RFamide-immunoreactive cells. [6]

Life cycle

Clava multicornis reproduces sexually as the larvae are fertilized in the gonophores on an adult female. The planulae hatch 48–72 hours after. [4] They then develop on the polyp where they are hatched into a 600–800-μm-long tadpole-like larvae. Its body shape is similar to a tadpole in that it tapers from the anterior to the posterior pole. However, its swimming stays close to the substrate and moves by ciliary gliding toward light. It also crawls by using its mucous gland cells. The larvae attaches on the anterior end once it has found an adequate environment to settle. [2] The posterior end then forms the mouth and tentacles. [4] This cnidarian never exhibits a medusa life stage. [2] Sexual reproduction can only be done in the prime temperature range of the species. [7]

Clava multicornis also reproduces asexually through budding from its polyp form. The asexual reproduction cycle reaches maximum reproduction rates at about 39 days in temperatures on the higher scale of their prime range. However, the species can reproduce asexually in a wider range of temperatures than during sexual reproduction. [7]

Behavior

Locomotion

As planulae crawl along the substrate with ciliary gliding, they move with their anterior end forward. This movement demonstrates a left and right bending in order to glide forward. Once in the adult polyp form, they stay attached to the substrate throughout the rest of their life. [2] Additionally, these planulae exhibit positive phototactic behavior (moving towards the light source). They have become a model for determining effects of retinoic acid (used to regulate physiological processes in chordates) on this phototropic behavior. [6]

Environment

During settlement of the planulae, C. multicornis tends to settle in colonies. [7] Additionally, they settle during periods of higher tides rather than lower tides. This is because they prefer to settle when algae are in a sloped or vertical position. [8] This position is likely when sea level rises and fronds float vertically.

In unfavorable time-periods of their environment, adult forms of C. multicornis can become dormant in order to survive. Their hydranth, a feeding zooid, rests in the stolon and begins to emerge once the environment is safe again. [3] Regeneration of their colonies follows this time period. Because of this ability to become dormant, they have been found to live in the Arctic. [9]

Habitat

Clava multicornis are sensitive to temperature. In their prime temperature range of 12 °C to 17 °C, the species can withstand many salinities ranging from 16 ppt to 40 ppt. [10] However, the species can flourish in 32 ppt environments. [7] One specific environment that they have been found in is the Arctic. [9] They attach to algal species including Ascophyllum nodosum and Fucus vesiculosus . [11]

The species tends to live in sheltered areas on algae away from shores because the planulae cannot settle when there is too much wave action. They can only feed efficiently in lesser currents because their tentacles become deformed from intense waves, causing their size to diminish. Further, when the planula larvae develop, they settle close to the bottom and middle of the algae since they are fragile against waves. They also may live away from shores because they are fragile to solar radiation. [12]

This species also houses other invertebrates. One known species is the larvae of Pycnogonum litorale , a sea spider who lives as an ectoparasite on C. multicornis either in its stolon or hydrocaulus. [13]

Phylogeny

Clava multicornis was originally specified under the family Clavidae but it was moved to family Hydractiniidae due to its similarities to other members of this family. The similarities that placed them in the family include having stolons growing off of its skeleton and a variation in the formation of polyps. [14] The most recent study from 2015 confirmed this, placing the species also in Filifera III. [15]

Related Research Articles

<span class="mw-page-title-main">Cnidaria</span> Aquatic animal phylum having cnydocytes

Cnidaria is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, including jellyfish, hydroids, sea anemone, corals and some of the smallest marine parasites. Their distinguishing features are a decentralized nervous system distributed throughout a gelatinous body and the presence of cnidocytes or cnidoblasts, specialized cells with ejectable flagella used mainly for envenomation and capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick.

<span class="mw-page-title-main">Polyp (zoology)</span> One of two forms found in the phylum Cnidaria (zoology)

A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are roughly cylindrical in shape and elongated at the axis of the vase-shaped body. In solitary polyps, the aboral end is attached to the substrate by means of a disc-like holdfast called a pedal disc, while in colonies of polyps it is connected to other polyps, either directly or indirectly. The oral end contains the mouth, and is surrounded by a circlet of tentacles.

<span class="mw-page-title-main">Hydrozoa</span> Class of cnidarians

Hydrozoa is a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in freshwater habitats. Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria.

<i>Obelia</i> Genus of hydrozoans

Obelia is a genus of hydrozoans, a class of mainly marine and some freshwater animal species that have both polyp and medusa stages in their life cycle. Hydrozoa belongs to the phylum Cnidaria, which are aquatic organisms that are relatively simple in structure with a diameter around 1mm. There are currently 120 known species, with more to be discovered. These species are grouped into three broad categories: O. bidentata, O. dichotoma, and O. geniculata. O. longissima was later accepted as a legitimate species, but taxonomy regarding the entire genus is debated over.

<span class="mw-page-title-main">Anthozoa</span> Class of cnidarians without a medusa stage

Anthozoa is a class of marine invertebrates which includes the sea anemones, stony corals and soft corals. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plankton. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being formed by the budding of new polyps from an original, founding individual. Colonies are strengthened by calcium carbonate and other materials and take various massive, plate-like, bushy or leafy forms.

<span class="mw-page-title-main">Nerve net</span> Nervous systems lacking a brain

A nerve net consists of interconnected neurons lacking a brain or any form of cephalization. While organisms with bilateral body symmetry are normally associated with a condensation of neurons or, in more advanced forms, a central nervous system, organisms with radial symmetry are associated with nerve nets, and are found in members of the Ctenophora, Cnidaria, and Echinodermata phyla, all of which are found in marine environments. In the Xenacoelomorpha, a phylum of bilaterally symmetrical animals, members of the subphylum Xenoturbellida also possess a nerve net. Nerve nets can provide animals with the ability to sense objects through the use of the sensory neurons within the nerve net.

A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and also in some species of Ctenophores. Some groups of Nemerteans also produce larvae that are very similar to the planula, which are called planuliform larva.

<span class="mw-page-title-main">Medusozoa</span> Clade of marine invertebrates

Medusozoa is a clade in the phylum Cnidaria, and is often considered a subphylum. It includes the classes Hydrozoa, Scyphozoa, Staurozoa and Cubozoa, and possibly the parasitic Polypodiozoa. Medusozoans are distinguished by having a medusa stage in their often complex life cycle, a medusa typically being an umbrella-shaped body with stinging tentacles around the edge. With the exception of some Hydrozoa, all are called jellyfish in their free-swimming medusa phase.

<i>Pelagia noctiluca</i> Species of cnidarian

Pelagia noctiluca is a jellyfish in the family Pelagiidae and the only currently recognized species in the genus Pelagia. It is typically known in English as the mauve stinger, but other common names are purple-striped jelly, purple stinger, purple people eater, purple jellyfish, luminous jellyfish and night-light jellyfish. In Greek, pelagia means "(she) of the sea", from pelagos "sea, open sea"; in Latin noctiluca is the combining form of nox, "night"", and lux, "light"; thus, Pelagia noctiluca can be described as a marine organism with the ability to glow in the dark (bioluminescence). It is found worldwide in tropical and warm temperate seas, although it is suspected that records outside the North Atlantic region, which includes the Mediterranean and Gulf of Mexico, represent closely related but currently unrecognized species.

<i>Turritopsis dohrnii</i> Species of small, biologically immortal jellyfish

Turritopsis dohrnii, also known as the immortal jellyfish, is a species of small, biologically immortal jellyfish found worldwide in temperate to tropic waters. It is one of the few known cases of animals capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary individual. Others include the jellyfish Laodicea undulata and species of the genus Aurelia.

<i>Chrysaora hysoscella</i> Species of jellyfish

Chrysaora hysoscella, the compass jellyfish, is a common species of jellyfish that inhabits coastal waters in temperate regions of the northeastern Atlantic Ocean, including the North Sea and Mediterranean Sea. In the past it was also recorded in the southeastern Atlantic, including South Africa, but this was caused by confusion with close relatives; C. africana, C. fulgida and an undescribed species tentatively referred to as "C. agulhensis".

<span class="mw-page-title-main">Hydroidolina</span> Subclass of hydrozoans

Hydroidolina is a subclass of Hydrozoa and makes up 90% of the class. Controversy surrounds who the sister groups of Hydroidolina are, but research has shown that three orders remain consistent as direct relatives: Siphonophorae, Anthoathecata, and Leptothecata.

<span class="mw-page-title-main">Leptothecata</span> Order of cnidarians with hydrothecae

Leptothecata, or thecate hydroids, are an order of hydrozoans in the phylum Cnidaria. Their closest living relatives are the athecate hydroids, which are similar enough to have always been considered closely related, and the very apomorphic Siphonophorae, which were placed outside the "Hydroida". Given that there are no firm rules for synonymy for high-ranked taxa, alternative names like Leptomedusa, Thecaphora or Thecata, with or without the ending emended to "-ae", are also often used for Leptothecata.

<span class="mw-page-title-main">Sea anemone</span> Marine animals of the order Actiniaria

Sea anemones are a group of predatory marine invertebrates constituting the order Actiniaria. Because of their colourful appearance, they are named after the Anemone, a terrestrial flowering plant. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra. Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle.

<i>Millepora platyphylla</i> Species of hydrozoan

Millepora platyphylla is a species of fire coral, a type of hydrocoral, in the family Milleporidae. It is also known by the common names blade fire coral and plate fire coral. It forms a calcium carbonate skeleton and has toxic, defensive polyps that sting. It obtains nutrients by consuming plankton and via symbiosis with photosynthetic algae. The species is found from the Red Sea and East Africa to northern Australia and French Polynesia. It plays an important role in reef-building in the Indo-Pacific region. Depending on its environment, it can have a variety of different forms and structures.

<i>Euphyllia ancora</i> Species of coral

Euphyllia ancora is a species of hard coral in the family Euphylliidae. It is known by several common names, including anchor coral and hammer coral, or less frequently as sausage coral, ridge coral, or bubble honeycomb coral.

<i>Turritopsis nutricula</i> Species of hydrozoan

Turritopsis nutricula is a small hydrozoan that once reaching adulthood, can transfer its cells back to childhood. This adaptive trait likely evolved in order to extend the life of the individual. Several different species of the genus Turritopsis were formerly classified as T. nutricula, including the "immortal jellyfish" which is now classified as T. dohrnii.

<i>Clytia hemisphaerica</i> Species of hydrozoan

Clytia hemisphaerica is a small hydrozoan-group cnidarian, about 1 cm in diameter, that is found in the Mediterranean Sea and the North-East Atlantic Ocean. Clytia has the free-swimming jellyfish form typical of the Hydrozoa, as well as vegetatively propagating polyps.

<span class="mw-page-title-main">Rosalindidae</span>

Rosalindidae is a family of cnidarians belonging to the order Anthoathecata.

Tima nigroannulata, commonly known as the elegant jellyfish, is a recently discovered colonial hydrozoa found on the Pacific coast of Japan.

References

  1. ↑ "WoRMS - World Register of Marine Species - Clava multicornis (Forsskål, 1775)". www.marinespecies.org. Retrieved 2020-04-03.
  2. 1 2 3 4 5 6 7 8 9 Piraino, Stefano; Zega, Giuliana; Di Benedetto, Cristiano; Leone, Antonella; Dell'Anna, Alessandro; Pennati, Roberta; Candia Carnevali, Daniela; Schmid, Volker; Reichert, Heinrich (2011-07-01). "Complex neural architecture in the diploblastic larva of Clava multicornis (Hydrozoa, Cnidaria)". The Journal of Comparative Neurology. 519 (10): 1931–1951. doi: 10.1002/cne.22614 . PMID   21452245. S2CID   28538197.
  3. 1 2 Calder, Dale (2014). "Clava multicornis (Forsskål, 1775): rediscovery of a North Atlantic hydroid (Cnidaria, Hydrozoa, Anthoathecata) on the Pacific coast of North America". BioInvasions Records. 3 (2): 71–76. doi: 10.3391/bir.2014.3.2.03 .
  4. 1 2 3 4 5 6 Pennati, Roberta; Dell’Anna, Alessandro; Pagliara, Patrizia; Scarì, Giorgio; Piraino, Stefano; De Bernardi, Fiorenza (2013). "Neural system reorganization during metamorphosis in the planula larva of Clava multicornis (Hydrozoa, Cnidaria)". Zoomorphology. 132 (3): 227–237. doi:10.1007/s00435-013-0188-1. ISSN   0720-213X. S2CID   18702245.
  5. ↑ Gold, David A.; Nakanishi, Nagayasu; Hensley, Nicholai M.; Hartenstein, Volker; Jacobs, David K. (2016). "Cell tracking supports secondary gastrulation in the moon jellyfish Aurelia". Development Genes and Evolution. 226 (6): 383–387. doi:10.1007/s00427-016-0559-y. ISSN   0949-944X. PMID   27535146. S2CID   33741460.
  6. 1 2 3 Pennati, Roberta; Dell'Anna, Alessandro; Zega, Giuliana; De Bernardi, Fiorenza; Piraino, Stefano (2013). "Retinoic acid influences antero-posterior positioning of peptidergic neurons in the planula larva of the hydrozoan Clava multicornis". Marine Ecology. 34: 143–152. Bibcode:2013MarEc..34..143P. doi:10.1111/maec.12032.
  7. 1 2 3 4 Kinne, Otto; Paffenhöfer, Gustav-Adolf (1966). "Growth and reproduction as a function of temperature and salinity inClava multicornis (Cnidaria, Hydrozoa)". Helgoländer Wissenschaftliche Meeresuntersuchungen. 13 (1–2): 62–72. Bibcode:1966HWM....13...62K. doi: 10.1007/bf01612656 . ISSN   0017-9957.
  8. ↑ Marfenin, N.N.; Belorustseva, S.A. (2008). "How the distribution of colonies of the hydroid Laomedea flexuosa is limited to a narrow belt along the lower littoral zone". Journal of the Marine Biological Association of the United Kingdom. 88 (8): 1559–1566. doi:10.1017/S0025315408002270. ISSN   0025-3154. S2CID   84916301.
  9. 1 2 Ronowicz, Marta; Kukliński, Piotr; Mapstone, Gillian M. (2015-03-20). Thuesen, Erik V. (ed.). "Trends in the Diversity, Distribution and Life History Strategy of Arctic Hydrozoa (Cnidaria)". PLOS ONE. 10 (3): e0120204. Bibcode:2015PLoSO..1020204R. doi: 10.1371/journal.pone.0120204 . ISSN   1932-6203. PMC   4368823 . PMID   25793294.
  10. ↑ Kinne, Otto; Paffenhöfer, Gustav-Adolf (1965). "Hydranth structure and digestion rate as a function of temperature and salinity inClava multicornis (Cnidaria, Hydrozoa)". Helgoländer Wissenschaftliche Meeresuntersuchungen. 12 (4): 329–341. Bibcode:1965HWM....12..329K. doi: 10.1007/BF01612558 . ISSN   0017-9957.
  11. ↑ Orlov, D. (1996). "Observations on the settling behaviour of planulae of Clava multicornis Forskaal (Hydroidea, Athecata)". Scientia Marina. 60: 121–128 – via ProQuest.
  12. ↑ Rossi, Sergi; Gili, Josep Maria; Hugues, R. G. (2000-12-30). "The effects of exposure to wave action on the distribution and morphology of the epiphytic hydrozoans Clava multicornis and Dynamena pumila". Scientia Marina. 64 (S1): 135–140. doi: 10.3989/scimar.2000.64s1135 . ISSN   1886-8134.
  13. ↑ Wilhelm, E.; Bückmann, D.; Tomaschko, K.-H. (1997-10-29). "Life cycle and population dynamics of Pycnogonum litorale (Pycnogonida) in a natural habitat". Marine Biology. 129 (4): 601–606. doi:10.1007/s002270050202. ISSN   0025-3162. S2CID   84261650.
  14. ↑ Cartwright, Paulyn; Evans, Nathaniel M.; Dunn, Casey W.; Marques, Antonio C.; Miglietta, Maria Pia; Schuchert, Peter; Collins, Allen G. (2008). "Phylogenetics of Hydroidolina (Hydrozoa: Cnidaria)". Journal of the Marine Biological Association of the United Kingdom. 88 (8): 1663–1672. doi:10.1017/S0025315408002257. hdl: 1808/15806 . ISSN   0025-3154. S2CID   30347781.
  15. ↑ Kayal, Ehsan; Bentlage, Bastian; Cartwright, Paulyn; Yanagihara, Angel A.; Lindsay, Dhugal J.; Hopcroft, Russell R.; Collins, Allen G. (2015-11-19). "Phylogenetic analysis of higher-level relationships within Hydroidolina (Cnidaria: Hydrozoa) using mitochondrial genome data and insight into their mitochondrial transcription". PeerJ. 3: e1403. doi: 10.7717/peerj.1403 . ISSN   2167-8359. PMC   4655093 . PMID   26618080.
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