|Slate pencil urchin|
|Slate pencil urchin on a brain coral|
|Range of slate pencil urchin|
Cidarites tribuloides, Lamarck, 1816 Cidaris tribuloides
Eucidaris tribuloides, the slate pencil urchin, is a cidaroid sea urchin that inhabits littoral regions of the Atlantic Ocean. As a member of the basal echinoid order Cidaroida, its morphological, developmental and molecular genetic characteristics make it a phylogenetically interesting species.
Distribution and habitat
From the United States to Brazil on the west to Mauritania to Gabon on the east, the slate pencil urchin can be found on both sides of the Atlantic, at the mid-Atlantic ridge and throughout the Caribbean. On the western side of the Atlantic, the slate pencil urchin has been found as far north as Cape Hatteras, North Carolina and as far south as Rio de Janeiro. In the Gulf of Mexico, populations have been reported at Alacran Reef, Campeche Bank. On the eastern side of the Atlantic, a closely related sub-species, Eucidaris tribuloides var. africana, has been reported at Cape Verde Islands, in the Gulf of Guinea, and at the Azores and Ascension Islands.
E. tribuloides has become an invasive species in some parts of the world including Maltese waters where it has been since 1998. This was the first record in the Mediterranean and is thought to have been brought there in ballast water.
McPherson described E. tribuloides as a "sluggish echinoid" that leads a nocturnal, benthic existence. During daylight hours, the slate pencil urchin uses its large primary spines to anchor itself under or atop rocks or to lodge itself in crevices. Individuals rarely stray far from their locality. At night, they will feed primarily on corals and sponges, among other things.
When its development is contrasted to the cidaroid sister subclass Euechinoidea, E. tribuloides becomes a very interesting organism from the standpoint of developmental and evolutionary biology. In euechinoid embryonic development, e.g. in the purple sea urchin, the micromeres comprise a set of four small cells that reside at the base of the vegetal plate. They are a "precociously invaginating lineage", meaning that they move into the blastocoel just prior to gastrulation; these four cells then eventually give rise to the larval skeleton. Similarly, E. tribuloides also possesses a larval skeleton that arises from a special lineage of cells. In contrast, however, the number and size of its micromeres can vary (from one to three), and they do not precociously invaginate; rather, they ingress during gastrulation and bud off from the tip of the growing archenteron. Although there are numerous molecular differences between the "spicule-forming cells" of E. tribuloides and the primary mesencyhme cells of euechinoids, these two cell lineages are thought to be homologous and have been contrasted in developmental evolution research.
Reproduction in E. tribuloides seems to be sensitive to both seasonal cycles and the lunar cycle. In the Florida Keys, E. tribuloides was found to obtain peak gravidity in the late summer and early fall. Populations in Panama, however, were found to be gravid in the spring, summer and fall, with peak gravidity occurring around the full moon.
- Kroh, Andreas (2012). "Eucidaris tribuloides (Lamarck, 1816)". World Register of Marine Species. Retrieved 2013-03-21.
- Schroeder, TE (1981). "Development of a 'primitive' sea urchin (Eucidaris tribuloides): irregularities in the hyaline layer, micromeres, and primary mesenchyme". Biological Bulletin. Marine Biological Laboratory. 161 (1): 141–151. doi:10.2307/1541114. JSTOR 1541114.
- Lamarck J (1816). Histoire naturelle des animaux sans vertèbres, présentant les caractères généraux et particuliers de ces animaux, Tome 3. p. 56.
- Pomel NA (1883). Classification methodique et genera des echinides vivants et fossiles. p. 103.
- Döderlein LHP (1887). Die japanischen Seeigel, I. Familie Cidaridae und Saleniidae. Stuttgart. p. 42.
- McPherson, BF (1968). "Contributions to the biology of the sea urchin Eucidaris tribuloides (Lamarck)". Bulletin of Marine Science. 18: 400–443.
- Cerame-Vivas, MJ; Gray IE (1966). "The distributional pattern of benthic invertebrates of the continental shelf off North Carolina". Ecology. Ecological Society of America. 47 (2): 260–270. doi:10.2307/1933773. JSTOR 1933773.
- Bernasconi I (1955). "Equinoideos y asteroideos de la coleccion del Instituto Oceanografico de la Universidad de San Pablo". Boletim do Instituto Oceanográfico. São Paulo. 6: 51–77. doi:10.1590/s0373-55241955000100002.
- Kornicker LS, Bonet F, Cann R & Hoskin CM (1959). "Alacran Reef, Campeche Bank, Mexico". Publications of the Institute of Marine Science. 6: 1–22.
- Mortensen, T (1928). A monograph of the Echinoidea 1, Cidaroides. Copenhagen: C.A. Reitzel. p. 551.
- Sciberras, M.; Schembri, P.J. (2007). "A critical review of records of alien marine species from the Maltese Islands and surrounding waters (Central Mediterranean)". Mediterranean Marine Science. 8 (1): 41–66. doi:10.12681/mms.162.
- Santos CP, Coutinho AB, Hajdu E (2002). "Spongivory by Eucidaris tribuloides from Salvador, Bahia (Echinodermata: Echinoidea)". Journal of the Marine Biological Association of the United Kingdom. 82 (2): 295–297. doi:10.1017/S0025315402005477.
- Boveri, T (1901a). "Die Polarität der Oocyte, Ei und Larve von Strongylocentrotus lividus". Zoologische Jahrbücher. Abteilung für Anatomie und Ontogenie der Tiere. 14: 630.
- Boveri, T (1901b). "Über die polarität des Seeigel-Eies". Verhandlungen der Physikalisch-medizinische Gesellschaft zu Würzburg. 34: 145.
- Hörstadius, S (1935). "Über die determination im Verlaufe der Eiacse bei Seeigeln". Pubblicazioni della Stazione Zoologica di Napoli. 14: 251.
- Tennent, DH (1914). "The early influence of the spermatozoan upon the characters of echinoid larvae". Carnegie Institution of Washington Publication. 182: 129–138.
- Wray GA, McClay DR (1988). "The origin of spicule-forming cells in a "primitive" sea urchin (Eucidaris tribuloides) which appears to lack primary mesenchyme cells". Development. 103 (2): 305–315. PMID 3066611.
- Erkenbrack EM, Davidson EH (2015). "Evolutionary rewiring of gene regulatory network linkages at divergence of the echinoid subclasses". Proceedings of the National Academy of Sciences of the United States. 112 (30): E4075–E4084. doi:10.1073/pnas.1509845112. PMID 26170318.
- Erkenbrack EM; et al. (2016). "Ancestral state reconstruction by comparative analysis of a GRN kernel operating in echinoderms". Development Genes and Evolution. 226 (1): 37–45. doi:10.1007/s00427-015-0527-y. PMID 26781941.
- Lessios H (1991). "Presence and absence of monthly reproductive rhythms among eight Caribbean echinoids off the coast of Panama". Journal of Experimental Marine Biology and Ecology. 153: 27–47. doi:10.1016/S0022-0981(05)80004-8.
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