User:Abbylsinclair/sandbox
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Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Araucariales |
| Family: | Araucariaceae |
| Genus: | Agathis |
| Species: | A. australis
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| Binomial name | |
| Agathis australis (D.Don) Loudon
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Patiriella regularis, the New Zealand common cushion star, is a sea star of the family Asterinidae, native to New Zealand.
Description
[edit]New Zealand is home to a rich abundance of endemic asteroid fauna[1]. Patiriella Regularis is one of these species and was originally described by Verill in 1867 as Asterina Regularis, and then in 1913 Verrill described the new genus Patiriella, naming Patiriella Regularis as the type species for this genus[1]. Asteroidea is one of five classes of echinoderm, the others being Ophiuroidea, Crinoidea, Echinoidea and Holothuroidea[2].
Patiriella Regularis is a spinulosan asterinid with a pentagonal shape[3]. It typically has five short arms, however, 2% of the population is composed of individuals with 4, 6, 7 or 8 arms[3]. It has an arm spread of up to 60 mm (2.4 in)[3]. The colour of Patiriella Regularis differs greatly between individuals and includes, blues, greens, browns as the more common colours identified, while oranges and reds and individuals with mottled forms have also been identified[1]. Two separate forms of Patiriella Regularis have been identified[4]. The most significant difference between the two is the plate arrangement along the ray crests[4]. They typically grow up to 10cm across in diameter, although their sizes vary greatly within the species[1].
Range
[edit]Natural global range
[edit]Although endemic to New Zealand, Patiriella Regularis has also spread to Southern Australia and Tasmania (Mills. et al. 2014). This spread is likely due to mussel exports in the 19th century.[1] Establishing populations in Tasmania are bordering on becoming labelled an invasive species due to their effects on the native fauna in those habitats[2]. Patiriella Regularis is the most commonly found asteroid in New Zealand and tends to dominate most suitable habitats[5]. They range the full length of New Zealand, from the North Cape to Stewart Island[1]. They are endemic to New Zealand, however have also spread to southern Australia and Tasmania[2]. Patiriella Regularis is abundant in many harbours around New Zealand, including Otago Harbour and Whangateau Harbour, at opposite ends of the country[1]. They are frequently found in the Fiordland of New Zealand, specifically throughout the Doubtful and Milford Sounds[6]. Patiriella Regularis is also found in the Kermadec Islands, a subtropical island group 1000km northeast of the North Island[5]. This starfish is common in the shallow depths of these waters within the low salinity layer (LSL), a depth of between <1-12m that typically has a low diversity of species in comparison to below the LSL[6].
Habitat
[edit]Patiriella Regularis inhabit shallow waters in rocky reefs and sandy areas close to coastlines[4]. It is found in intertidal cobble fields as well as shallow and moderately deep rock pools[6]. This species lives on a wide range of substrates with small preference shown toward shell gravel substrates[1]. It is found on rocky substrates, sandy bottoms, amongst/on boulders, crushed shells and many other habitats[7].
Ecology
[edit]Life cycle/Phenology
[edit]Patiriella Regularis follows an annual reproductive cycle[8]. They reproduce asexually by fission and also sexually, males and females releasing eggs and sperm into the water for external fertilisation[1]. Reproductive success in Patiriella Regularis is dependent on environmental conditions that are the most favourable for success of the offspring, for example the abundance of food within the habitat[8]. Factors that affect gametogenesis are divided into two sections: exogenous factors and endogenous factors, referring to environmental variables and variables within the organism respectively[8]. One exogenous factor that affects or induces the cycle of asteroids is food availability. Where food abundances are low, the stored food reserves in the pyloric caeca of the asterinid will also be low, resulting in poor gonad development[3]. The reproductive cycle of females of Patiriella Regularis is divided into five stages: the recovery stage, the growing stage, the maturing stage, the partly-spawned stage and the spent stage[8]. These stages are characterised by the number of oocytes in each stage of development, the presence or absence of degenerating octets and the abundance of somatic cells[8]. The female Patiriella Regularis’ reproductive cycle follows a sequence of events from oogenesis, gonad activation, spawning of gametes, regression of gonadal activity and a resting period[8]. Oogenesis produces an ovum from a primordial germ cell with cell growth and organelle synthesis[8]. Patiriella Regularis is an oviparous animal, one which deposits eggs that hatch outside of their body[8]. Patiriella Regularis spawns eggs around the size of 150µm[3]. During the reproductive process for oviparous animals the gamete has to be prepared as a specialised cell that has the energy and nutrition required for the future embryo, as it cannot rely on the mother like viviparous organisms can[8]. It is during the most significant event of the reproductive cycle, oogenesis, that these nutrients are accumulated in the form of yolk proteins in the oocyte for future use by the embryo[8]. Ovarian activity peaks in the southern hemisphere summer months (December to January) followed by a gradual decrease towards the end of January through March[8]. Ovarian activity reaches its minimum value of 5% at the end of March, is stable through austral autumn and gradually begins to rise through winter before increasing almost two-fold between spring and summer[8]. This species of asteroid has a relationship with photoperiod as well as water temperature; as day length increases/water temperature increases, ovarian activity increases similarly and spawning occurs just after the longest day in the southern hemisphere towards the end of December[8]. The larval stage of Patiriella Regularis is consistent with the typical form of most asteroids, indirect development through the larval stages of bipinnaria and brachiolaria[9]. Bipinnaria is a bilaterally symmetrical starfish larva with two cilia bands, one at the front of the mouth and one at its back, for feeding and movement respectively[10]. The brachiolaria stage is the second stage in the larval sequence of asteroids[10]. Characterisation of this stage is by the possession of three short arms and movement via the external cilia[11]. Shade is a significant environmental cue for metamorphosis from larval stage to adult starfish, which in itself takes 5-6 days[9]. The cycle from egg to mature starfish takes, on average, two months to complete, although this is dependent on environmental conditions such as water temperature[11]. The cycle of Patiriella Regularis depends on particular environmental signals to become induced[11]. The starfish gather in groups prior to spawning to increase the chance of fertilisation, a behavioural factor that impacts their reproductive success[11].
Diet and foraging
[edit]Patiriella Regularis is an omnivore that predominantly feeds on crustose coralline algae and microorganisms[12]. It can act as a detritivore and consume dead flesh of other organisms[12]. Carrion is an important part of the diet of this asteroid and is linked to increased growth rates and reproduction[12]. Common prey includes sponges, annelids, gastropods, bivalves, crustaceans and ascidians[1]. Patiriella Regularis regularly competes with other organisms such as whelk over shared resources, specifically mussel flesh[12]. This starfish can prey on very small organisms such as gastropods and can also feed on the Elminius modestus barnacle[1]. Diet and energy intake is key to population survival, with a direct link between well fed populations and increased growth rate and gonad activity[1]. The opposite is true with poorly fed populations, they seem to show minimal growth and reproductive activity[1]. Populations with surplus feeding resources can reach breeding maturity within a year of metamorphosis, despite the usual time taking three years[1]. The digestive system starts with the mouth that directly leads to the cardiac stomach[1]. In a relaxed state the cardiac stomach is gathered in folds within the body[1]. Patiriella Regularis can evert its stomach to digest substrate externally, the degree of eversion dependent on the food type and therefore by the environment and substrate type[1]. Circumferential fibres seperate the ventral cardiac stomach from the pyloric stomach, which is the second compartment that is responsible for further digesting what the cardiac stomach partially digests[1].
Predators, Parasites, and Diseases
[edit]Mass mortality of Patiriella Regularis is often due to a disease commonly coined ‘sea star wasting disease’, scientifically referred to as ‘asteroid idiopathic wasting syndrome’[7]. Investigation of infected individuals revealed they were inhabited by a host of copiotrophic bacteria - bacteria that consumes organic matter rapidly[7]. This indicates that sea-star ‘wasting’ is not necessarily a virus; it is a result of a congregation of organic matter that encourages microbial respiration[7]. This results in oxygen depletion in the outer asteroid tissue responsible for diffusion and respiration[7]. Research suggests that Patiriella Regularis is host to a great diversity of undiscovered microbes of varying parasitic and symbiotic relationships[7]. Mesomycetozoea are a small clade of opisthokonta and are parasites of many aquatic species[7]. They were identified in the epidermal cells of Patiriella Regularis and found widespread in coastal habitats of New Zealand; thus they are predicted to be a regularly occurring inhabitant of the sea star[7]. This eukaryote can form dermal infections due to their occurrence in epidermal tissues[7]. Patiriella Regularis is preyed on by a variety of larger organisms such as fish, rays, shorebirds, crabs and other Asteroid species[1]. Sea stars in the larval stages of bipinnaria and brachiolaria are particularly at risk of predation[1].
Cultural uses
[edit]Patiriella Regularis is not used specifically for cultural purposes, however it does play an important role in aquatic ecosystems and can be used as an indicator of water quality[12].
References
[edit]- ^ a b c d e f g h i j k l m n o p q r s t Crump, R. (1969) Aspects of the biology of some New Zealand echinoderms : feeding, growth and reproduction in the asteroids, Patiriella regularis (Verrill, 1867) and Coscinasterias calamaria (Gray, 1840). https://ourarchive.otago.ac.nz/esploro/outputs/+doctoral/Aspects-of-the-biology-of-some/9926480065701891
- ^ a b c Mills. Et al (2014). Extraordinary Echinoderms - a guide to the echinoderms of New Zealand. https://webstatic.niwa.co.nz/static/extraordinary_echinoderms.pdf
- ^ a b c d e Crump, Robin G. (1971-07-01). "Annual reproductive cycles in three geographically separated populations of Patiriella regularis (Verrill), a common New Zealand asteroid". Journal of Experimental Marine Biology and Ecology. 7 (2): 137–162. doi:10.1016/0022-0981(71)90028-1. ISSN 0022-0981.
- ^ a b c O'Loughlin, P. M.; and Roy, M. S. (2002-12-01). "Description of a new species of Patiriella from New Zealand, and review of Patiriella regularis (Echinodermata, Asteroidea) based on morphological and molecular data". Journal of the Royal Society of New Zealand. 32 (4): 697–711. doi:10.1080/03014223.2002.9517716. ISSN 0303-6758.
{{cite journal}}:|first2=missing|last2=(help)CS1 maint: multiple names: authors list (link) - ^ a b Townsend. M. Et al. (2010) Ecological Communities and Habitats of Whangateau Harbour 2009. https://knowledgeauckland.org.nz/media/1790/tr2010-057-whangateauecological-monitoring.pdf
- ^ a b c Barker, Mike F.; Russell, Michael P. (2008-02). "The distribution and behaviour of Patiriella mortenseni and P. regularis in the extreme hyposaline conditions of the Southern New Zealand Fiords". Journal of Experimental Marine Biology and Ecology. 355 (1): 76–84. doi:10.1016/j.jembe.2007.12.001.
{{cite journal}}: Check date values in:|date=(help) - ^ a b c d e f g h i Hewson, Ian; Sewell, Mary A. (2021-04-22). "Surveillance of densoviruses and mesomycetozoans inhabiting grossly normal tissues of three Aotearoa New Zealand asteroid species". PLOS ONE. 16 (4): e0241026. doi:10.1371/journal.pone.0241026. ISSN 1932-6203. PMC 8061988. PMID 33886557.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ a b c d e f g h i j k l m Alquaisi. K. M et al. (2023). The Reproductive Cycle of the Female Cushion Sea Star. https://www.rscn.org.jo/uploaded_files/journal/6763f29f8e04c1734603423.pdf
- ^ a b Byrne, M; Gonzalez-Bernat, M; Doo, S; Foo, S; Soars, N; Lamare, M (2013-01-21). "Effects of ocean warming and acidification on embryos and non-calcifying larvae of the invasive sea star Patiriella regularis". Marine Ecology Progress Series. 473: 235–246. doi:10.3354/meps10058. ISSN 0171-8630.
- ^ a b McEdward, L. R.; Janies, D. A. (1993-06). "Life Cycle Evolution in Asteroids: What is a Larva?". The Biological Bulletin. 184 (3): 255–268. doi:10.2307/1542444. ISSN 0006-3185.
{{cite journal}}: Check date values in:|date=(help) - ^ a b c d Kelly, C. D. et al. (2015). Starfish Brachiolaria Larva. https://micro.magnet.fsu.edu/ optics/olympusmicd/galleries/brightfield/ starfishbrachiolarialarva.html#:~:text=After%20the%20gametes%20are%20matched,br achiolaria%20larval%20stage%20is%20reached.
- ^ a b c d e Palmer, Shiree (2010-01-01). The Ecological Role of a Common Seastar (Patiriella spp.) Within Intertidal Cobble Fields (thesis thesis). Open Access Te Herenga Waka-Victoria University of Wellington. doi:10.26686/wgtn.16969558.v1.