Exogone anomalochaeta Benham, 1921

Soto, Eulogio H. & Martín, Guillermo San, 2017, Exogoninae (Annelida: Syllidae) from Chilean Patagonia, Zootaxa 4353 (3), pp. 521-539 : 527

publication ID

https://doi.org/ 10.11646/zootaxa.4353.3.7

publication LSID

lsid:zoobank.org:pub:452992DC-3E00-4E57-9484-608D4463B8BB

DOI

https://doi.org/10.5281/zenodo.3510870

persistent identifier

https://treatment.plazi.org/id/EE67F120-3B72-FFC5-FF32-FCC6FCF4F8DD

treatment provided by

Plazi

scientific name

Exogone anomalochaeta Benham, 1921
status

 

Exogone anomalochaeta Benham, 1921 View in CoL

Figures 4–5 View FIGURE 4 View FIGURE 5

Exogone anomalochaeta Benham, 1921: 24 View in CoL , pl. 5, figs 11–13; 1927: 62, pl. 1, figs. 9– 10; Blankestein & Lana 1986: 62, figs 30–31 San Martín & Parapar 1997: 291; Barroso et al. 2017: 403 View Cited Treatment , figs. 1–2.

Exogone (Parexogone) tridentata Hartmann-Schröder, 1993: 143 View in CoL , figs. 20–21.

Material examined. Livingston Island , South Shetlands ( Antarctica), id. G. San Martín, 17 February 1994, 1 specimen ( MNCN 16.01 About MNCN /1518) ; same location, 19 February 1994, 24 specimens ( MNCN 16.01 About MNCN /1518), (4 SEM) ; same location, 7 February 1994, 4 specimens ( MNCN 16.01 About MNCN /1517) ; same location, 30 January 1995, 1 specimen ( MNCN 16.01 About MNCN /3540) ; same location, 18 January 1995, 3 specimens ( MNCN 16.01 About MNCN /3541).

Remarks and additions to description. The new species herein described, Exogone yagan , share the lack of spiniger-like chaetae with E. anomalochaeta , an Antarctic species. For this reason, we examined specimens deposited in the MNCNM, collected and reported by San Martín & Parapar (1997). These specimens agree with the previous descriptions, except for the absence of dorsal cirri on chaetiger 2 ( Figs 4A View FIGURE 4 , 5A View FIGURE 5 ); this character is described in the previous descriptions but in Benham 1921, fig. 11, the drawing shows dorsal cirri on chaetiger 2; at that time, the importance of the presence or absence of dorsal cirri on chaetiger 2 was not known to separate species of Exogone , and usually they were figured although not present. The compound chaetae are all thick, with distally enlarged shafts and numerous distal and subdistal spines ( Figs 4C, E, G View FIGURE 4 ), and very short, almost included inside the distal, spinose part of the shafts, named as “gomphotric chaetae” by Benham 1921, 1927. The dorsal simple chaetae are the typical of the genus ( Figs 4B, F View FIGURE 4 , 5B, C, E View FIGURE 5 ), but some in the mid-body are distally enlarged, and having a spatulate appearance ( Fig. 4D View FIGURE 4 ). Apparently, this species lacks ventral simple chaetae, since they have not been described by any author and we have not found these in the material examined.

Barroso et al. (2017) recently redescribed this species in bases of material collected in Brazil between 749 and 1050 m depth. These specimens agree well with the Antarctic specimens, except by having ventral simple chaetae and longer proventricle (3.5–5 segments instead of 2–3 segments); it is possible that they could belong to two different species, but would be necessary more detailed studies to separate them.

Habitat. In mud. Intertidal to 1000 m.

Distribution. Antarctic and sub-Antarctic seas. Brazil.

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Order

Phyllodocida

Family

Syllidae

Genus

Exogone

Loc

Exogone anomalochaeta Benham, 1921

Soto, Eulogio H. & Martín, Guillermo San 2017
2017
Loc

Exogone (Parexogone) tridentata Hartmann-Schröder, 1993 : 143

Hartmann-Schroder 1993: 143
1993
Loc

Exogone anomalochaeta

Barroso 2017: 403
San 1997: 291
Lana 1986: 62
Benham 1921: 24
1921
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