Arbacia

Abstract

Gray named the regular sea urchin genus Arbacia (family Arbaciidae, order Arbacioida) in 1835. According to Agassiz (1842) and Mortensen (1935), Arbacia was a "nonsensical" name for a sea urchin genus. Harvey (1956) gave the most plausible explanation for the name, considering it a derivation of Arbaces, a secondary character in the historical poem Sardanapalus by Lord Byron, which was published in 1821, a few years before Gray's work. Arbacia is a small genus well known from Miocene age (Smith, 2005). All the members of this genus show morphological similarities (Mortensen, 1943). The test, formed from regularly arranged plates, is rather stout, flattened below, and gently domed above. The test has primary spines and tubercles; secondary spines are absent in the genus (Tortonese, 1965). The spines are moderate to long in length, often showing size and shape pattern differences with reference to body regions. In particular, those nearest to the mouth have enameled flattened tips. On the aboral side, there are usually conspicuous naked areas in the upper portions of the interambulacra. A large, more or less soft and membranous peristome, with an undulating edge characterizes the genus. The peristome may be naked, but it usually has small spines and pedicellariae and contains embedded plates that support the buccal podia. The periproct is largely covered by four subtriangular and subequal plates. The apical system has four large periproctal plates forming an anal valve. The size of Arbacia species ranges from approximately 15 to 50 mm in diameter (test without spines). The various species of Arbacia are usually colored uniformly, most commonly green, brown, purple, or black. Arbacia species occur in tropical, temperate, and sub-Antarctic zones. Six species of Arbacia have been described by Mortensen (1943):

The Two Sides of the Mediterranean: Population Genomics of the Black Sea Urchin Arbacia lixula (Linnaeus, 1758) in a Warming Sea

“…The two dominant sea urchins in shallow littoral communities are the purple (or common) sea urchin Paracentrotus lividus and the black sea urchin Arbacia lixula (Gianguzza, 2020). Both have different biological and ecological characteristics relevant for their potential impact.…”

Embryonic and larval development is conditioned by water temperature and maternal origin of eggs in the sea urchin Arbacia dufresnii (Echinodermata: Echinoidea)

“…This may generate an increased survival rate of larvae, due to food availability at low temperatures and, due to the speed of development at higher temperatures in Nuevo Gulf. In A. lixula, discrepancies were found in the optimal temperature for recruitment between populations from different regions (Privitera et al, 2011), probably indicating different strategies to achieve metamorphosis, depending on regional environmental factors, such as high temperature or available food (Privitera et al, 2011;Gianguzza, 2020). On the other hand, our results show that in A. dufresnii there is a strong progeny influence on larvae development.…”

“…Unlike other sea urchins, Arbacia species are found in tropical, temperate, and subantarctic areas (Gianguzza, 2020). Some studies indicate that A. lixula is a thermophilic (heat-tolerant) species (Gianguzza et al, 2011;Gianguzza et al, 2014;Pérez-Portela et al 2019), and may develop normally in an amplitude of 10 °C, with local differences depending on the thermal history prior to spawning (Gianguzza, 2020). A. dufresnii also presents a large distribution with different seawater temperatures (ranging from 23 ºC to 4 ºC).…”

“…In Arbacia lixula, better maternal nutritional status has been related to the high protein and lipid content of the eggs and to larval survival (George et al, 1990). However, in the Arbacia species, the available data relating to these topics is very limited and usually refers to A. lixula (Gianguzza, 2020).…”

Photoperiod in aquaculture of the sea urchin Arbacia dufresnii (Echinodermata: Echinoidea): Effects on gamete production and maturity

“…This control is thought to be determined by both endogenous and exogenous factors (Mercier & Hamel, 2009). In sea urchins, gametogenesis is initiated in response to external factors, such as temperature and photoperiod (Fuji, 1967;Pearse & Walker, 1986;Bay-Schmidt & Pearse, 1987;Byrne, 1990;Unuma, Konishi, Furuita, Yamamoto, & Akiyama, 1996;Meidel & Scheibling, 1998;Walker & Lesser, 1998;Spirlet, Grosjean, & Jangoux, 2000;Unuma, 2002;Kirchhoff, Eddy, & Brown, 2010;Gianguzza, & Bonaviri, 2013;Wangensteen, Turon, Casso, & Palacín, 2013;Díaz-Martínez, Carpizo-Ituarte, & Benítez-Villalobos, 2019). To be successful, any sea urchin aquaculture must take into account the factors regulating gametogenesis.…”