Agassizia excentrica A. Agassiz, 1869

Gondim, Anne Isabelley, Moura, Rafael Bendayan De, Christoffersen, Martin Lindsey & Dias, Thelma Lúcia Pereira, 2018, Taxonomic guide and historical review of echinoids (Echinodermata: Echinoidea) from northeastern Brazil, Zootaxa 4529 (1), pp. 1-72 : 46

publication ID

https://doi.org/ 10.11646/zootaxa.4529.1.1

publication LSID

lsid:zoobank.org:pub:B3EF69F4-7E42-4924-9A9F-FFF5D83022EB

DOI

https://doi.org/10.5281/zenodo.5971068

persistent identifier

https://treatment.plazi.org/id/C4255B09-4E1E-FFC0-FF55-1A2DFF74F84B

treatment provided by

Plazi

scientific name

Agassizia excentrica A. Agassiz, 1869
status

 

Agassizia excentrica A. Agassiz, 1869

Figure 16 View FIGURE 16 A–G

Agassizia excentrica A. Agassiz, 1869: 276 , pl. 11, figs 23–24.― Tommasi, 1972: 32 –33, fig. 66.― Manso, 2004: 21, fig. 2af.― Magalhães et al., 2005: 63.― Ventura et al., 2007a: 352.― Manso et al., 2008: 184 –185, figs 6e–f.― Oliveira et al., 2010: 11.

Material examined. Bahia: 1 spm, 12°56′13″S 38°33′55″W, 56 m [UFBA00369]; 2 spms, Busca Vida Beach, Guarajuba, Camaçari, I.2010, 37 m [UFBA01195]; 1 spm, Busca Vida Beach, Guarajuba, Camaçari, II.2008, 45 m [UFBA01196]; 2 spms, Busca Vida Beach, Guarajuba, Camaçari, II.2011, 37 m [UFBA01304]; 1 spm GoogleMaps , Baía de Camamu [UFSITAB-124]; 1 spm, without locality data, 07.XII.1978 [ MZUSP, without voucher]; 1 spm, without locality data [ MZUSP, without voucher] .

Description. Test small, oval or rounded, covered by long, slender, vitreous spines (TL = 7.4 to 15.3 mm; TH = 5.3 to 11 mm; TW = 6 to 13 mm) ( Fig. 16 View FIGURE 16 A–C). Apical system ethmolytic, displaced towards posterior region of test ( Fig. 16A, D, G View FIGURE 16 ). Four gonopores, posterior pores subtly larger than anterior pores ( Fig. 16G View FIGURE 16 ). Ambulacrum III weakly depressed, with very small podial pores ( Fig. 16A, D View FIGURE 16 ). Ambulacra II and IV weakly sunken, with two columns (one is rudimentary) of pore-pairs and three times longer and slightly slenderer than ambulacra I and V ( Fig. 16A, D View FIGURE 16 ). Ambulacra I and V slightly more sunken than anterior paired ambulacra (II and IV), with equally developed columns of pore-pairs ( Fig. 16A, D View FIGURE 16 ). Peripetalous fasciole well-developed and adjacent to paired petals (I, II, IV and V) ( Fig. 16A, C, D View FIGURE 16 ). Lateroanal fasciole present ( Fig. 16C, F View FIGURE 16 ). Cluster of long spines close to periproct. Periproct circular and longitudinal ( Fig. 16D View FIGURE 16 ), covered by plates of variable sizes and shapes, larger plates close to edge and smaller plates towards center. Peristome large, D-shaped, covered by many plates ( Fig. 16B, E View FIGURE 16 ). Labrum short and wide ( Fig. 16E View FIGURE 16 ), in broad contact with sternal plates, and not projecting strongly towards peristome. Amphisternous plastron, with many primary tubercles. Plastron spines large and spatulate ( Fig. 16B, E View FIGURE 16 ). Crenulate and perforate tubercles ( Fig. 16 View FIGURE 16 D–F). Aboral tuberculation fine, uniform, and dense ( Fig. 16D View FIGURE 16 ). Oral tubercles also dense and uniform ( Fig. 16E View FIGURE 16 ). Tube feet with spinules of variable shapes.

Pedicellariae. Ophicephalous pedicellariae distributed over entire test. Ophicephalous pedicellariae short and without a neck. Valves short, proximal region large, blade narrow with denticulate margin, which enlarges towards the tip, forming a foramen with denticulate margin.

Colour. Spines pinkish gray, darkest at the bases, in living specimens ( A. Agassiz 1883). Yellowish in alcohol. Naked test white.

Distribution. Florida, Gulf of Mexico, Mexico, Belize, Bahamas, Barbados, Cuba, Dominican Republic, Trinidad and Tobago, Honduras, Puerto Rico, Nicaragua, Panama, Colombia, Venezuela, Guyana, and Brazil (A.H. Clark et al. 1921; Tommasi 1972; Borrero-Pérez et al. 2002, 2012; Alvarado et al. 2008; Solís-Marín et al. 2013). In Brazil from BA ( Manso 2004). From depths of 43 to 900 m ( Pawson et al. 2009).

Remarks. The genus Agassizia presently consists of only two extant species [ A. excentrica and A. scrobiculata Valenciennes, 1846 ] ( Kroh & Mooi 2016). Agassizia excentrica is the only species in the genus recorded from the Atlantic Ocean. A. Agassiz (1869), in the original description, says that he was not sure that his specimen did not belong to A. porifera ( Ravenel, 1848) (fossil). Nevertheless, A. Agassiz (1869) presented a brief description of his new species and the features he used to distinguish it from other known species at that time, but did not provide illustrations. Although A. excentrica is well established taxonomically, a reanalysis of its type series and a redescription of this species is still needed. Few individuals were analyzed in the present paper, all of which were similar in size and without observed variations. A. Agassiz (1883, 1904) provided an extended discussion on the ontogenetic development of morphological characters of A. excentrica .

Ecological notes. Agassizia excentrica lives buried in sandy or sand-mud substrates. According to Lewis (1963), this species appears to have typical bottom feeding habits and ingests loose bottom material at random. This is a very rare species for which data on ecology and evolutionary biology are scarce. Along the Brazilian littoral, it has been found in fine sediments together with the ophiuroids Microphiopholis atra ( Stimpson, 1854) , Amphioplus camamuensis Manso, 2004 and Amphiodia pulchella ( Lyman, 1869) ( Manso 2004; Manso et al. 2008).

MZUSP

Museu de Zoologia da Universidade de Sao Paulo

Kingdom

Animalia

Phylum

Echinodermata

Class

Echinoidea

Order

Spatangoida

Family

Schizasteridae

Genus

Agassizia

Loc

Agassizia excentrica A. Agassiz, 1869

Gondim, Anne Isabelley, Moura, Rafael Bendayan De, Christoffersen, Martin Lindsey & Dias, Thelma Lúcia Pereira 2018
2018
Loc

Agassizia excentrica

Oliveira, J. P. & Oliveira, J. & Manso, C. L. C. 2010: 11
Manso, C. L. C. & Alves, O. F. S. & Martins, L. R. 2008: 184
Ventura, C. R. R. & Verissimo, I. & Nobre, C. C. & Zama, P. C. 2007: 352
Magalhaes, W. F. & Martins, L. R. & Alves, O. F. S. 2005: 63
Manso, C. L. C. 2004: 21
Tommasi, L. R. 1972: 32
Agassiz, A. 1869: 276
1869
GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF