Cossura, Webster & Benedict, 1887

Zhadan, Anna, 2015, Cossuridae (Annelida: Polychaeta: Sedentaria) from Australian and Adjacent Waters: the First Faunistic Survey, Records of the Australian Museum 67 (1), pp. 1-24: 16

publication ID

http://doi.org/ 10.3853/j.2201-4349.67.2015.1639

persistent identifier

http://treatment.plazi.org/id/2B16878E-FF97-D611-FEDD-FF2DC667B2A8

treatment provided by

Carolina

scientific name

Cossura
status

 

Cossura   sp. cf. longocirrata 

Webster & Benedict, 1887

Figs 12 View Figure 12 , 13 View Figure 13

Cossura longocirrata Webster & Benedict, 1887: 743   , pl. 8, figs 105–107. — Fournier & Petersen, 1991: 65, figs 1–2.

Type locality. Eastport , Maine   .

Material examined. New South Wales. 1 complete specimen, Pittwale (33°35'49"S 151°18'51"E), Ceridan Fraser’s Honour project, depth 15.8 m, sandy mud, coll. P.A. Hutchings, K.B. Attwood, C. Fraser, RV Baragula, NSW 2740, 02 Dec. 2004 GoogleMaps   , W.42959; 2 specimens, Pittwale (33°35'49"S 151°18'51"E), Ceridan Fraser’s Honour project, depth 15.8 m, sandy mud, coll. P.A. Hutchings, K.B. Attwood, C. Fraser, RV Baragula, NSW 2740, 02 Dec. 2004 GoogleMaps   , W.42960; 1 specimen, Pittwater (33°36'02"S 151°18'46"E), 25 Aug. 1994 GoogleMaps   , depth 16.1 m, mud, FAC2 05 Pit 2/2 B Australian Museum Party, W. 23619   ; 1 specimen, Hawkesbury River, near Hungry Beach (33°35'S 151°17'E), 27-V-83 1-1-1, depth 4 m, coll. A. R. Jones, A. Murray, Smith­McIntyre grab, sandy mud, W.43367 GoogleMaps   ; 1 specimen, Botany Bay , 200–500 m west of runway extension (33°57'49"S 151°10'26"E), F.A.C. Study, G6­2­4, NSW­772, April 1992 GoogleMaps   , depth 7 m, W.43325; 3 specimens, Hawkesbury River, near Hungry Beach (33°35'S 151°17'E), 04 Feb. 1983 GoogleMaps   , Hawkesbury River Survey, depth 4 m, Smith­McIntyre grab, sandy mud, coll. A. R. Jones, A. Murray, W. 43253   ; 1 specimen, Hawkesbury River, between Juno Head and Hungry Beach, mid­stream (33°34'S 151°16'E), Hawkesbury River Survey, depth 10 m, 06 Nov. 1981 GoogleMaps   , Smith-McIntyre grab, muddy sand, coll. A. R. Jones, A. Murray , W.43254   ; 24 specimens, Hawkesbury, Brooklyn Boat Channel (33°33'S 151°14'E), River Brooklin dredging, H. R. S. Polychaetes, 21 Aug. 1980 GoogleMaps   , coll. A. R. Jones et al., W.196734   .

Description. Complete specimen (W.42959) has 46 chaetigers, body length 5.6 mm, body width 200 μm.Another incomplete specimen is 300 μm in width, 2.3 mm in length having 27 chaetigers. 13–18 (in rare case 22–23) thoracic chaetigers without clear border between regions ( Figs 12A,B View Figure 12 , 13A View Figure 13 ). In thoracic region chaetae emerge from the anterior margin of segments, body flattened dorsoventrally, segments short. Methylen blue staining revealed dark, probably glandular cells on lateral and dorsal parts of segments, but segments are not inflated ( Figs 12H View Figure 12 , 13A View Figure 13 ). In abdominal region segments longer, body cylindrical, chaetae thinner and less numerous ( Figs 12A,B View Figure 12 , 13A View Figure 13 ).

Prostomium conical, not flattened, with pointed tip, without eyes, nuchal organs not seen ( Figs 12I View Figure 12 , 13B,C,F View Figure 13 ). Prostomial furrow well defined in contracted specimens, in well-relaxed specimens absent. Posterior prostomial ring shorter than peristomium. Lateral margins of both prostomial parts usually convex, less straight ( Figs 12B,F View Figure 12 , 13I View Figure 13 ). Branchial filament arising from posterior part of chaetiger 2; in contracted specimens looking as attached to border between chaetigers 2 and 3 ( Figs 12G,H View Figure 12 , 13B,C View Figure 13 ).

Chaetiger 1 with uniramous parapodia, all the next segments bear biramous ones. All chaetae hirsute capillaries; arranged in two rows. Thicker chaetae located in anterior row, thinner ones in posterior. First chaetiger bearing 4–7 chaetae, next up to 9 in notopodia and up to 10 in neuropodia. 3 thick anterior neuropodial chaetae thicker than 3 thick anterior notopopodial chaetae ( Figs 12E View Figure 12 , 13H,I View Figure 13 ). In posterior thoracic and abdominal chaetigers all chaetae becoming thinner, less numerous and less hirsute, 4–5 chaetae per ramus ( Figs 12G View Figure 12 , 13J View Figure 13 ).

Oocytes observed in body cavity in specimens from Pittwale (W.42960) and Hawkesbury River (W.43367).

Pygidium with three long anal cirri, without intercirral processes ( Figs 12F View Figure 12 , 13D View Figure 13 ). Cirri easily lost, in most specimens only one or two cirri present. In one specimen (W.42960) pygidium was regenerating ( Fig. 13B,C View Figure 13 ).

Remarks. This species closely resembled C. longocirrata Webster & Benedict, 1887   , having a conical prostomium, branchial filament inserted to chaetiger 2, no intercirral anal processes, absence of heavy acicular thoracic chaetae. Australian worms differ by generally less number of thoracic chaetigers (13–18, rarely up to 22, instead of 16–21 in C. longocirrata   ). But it is not clear if they really belong to a separate species or represent an example of intraspecific variability. Detailed redescription of numerous specimens from different localities including type material of C. longocirrata   was done by Fournier & Petersen (1991). They concluded it is a cold-temperate arctic-boreal species; it has usually been collected from below the halocline at a salinity of 30 or higher and a year-round bottom temperature below 5°C; it is doubtful whether C. longocirrata   occurs anywhere in the Pacific Ocean. The most probably Australian worms described here represent a separate species but we did not find morphological characters allowing to erect a new species. An analysis using molecular methods is required to solve this problem. Furthermore, in our material was also present a similar species C. sp. cf. pygodactylata   , that differs mostly by the presence of intercirral anal processes, but most specimens are incomplete, so there is a possibility that there is a mixture of two species in material referred to Cossura   sp. cf. longocirrata   .

RV

Collection of Leptospira Strains

R

Departamento de Geologia, Universidad de Chile

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Family

Cossuridae

Loc

Cossura

Zhadan, Anna 2015
2015
Loc

Cossura longocirrata

Webster & Benedict 1887: 743
1887