Halosydna hartmanae ( Kudenov, 1975 )

Salazar-Silva, Patricia, 2013, Revision of Halosydna Kinberg, 1856 (Annelida: Polychaeta: Polynoidae) from the Tropical Eastern Pacific and Grand Caribbean with descriptions of new species, Journal of Natural History 47 (17 - 18), pp. 1177-1242 : 1189-1192

Halosydna hartmanae ( Kudenov, 1975)

( Figures 5 , 6 )

Malmgrenia hartmanae Kudenov, 1975: 77–79 , figure 2.

Halosydna hartmanae: Hanley, 1987: 160 ; Salazar-Silva, 2006: 147.

Type material

Holotype LACM-AHF POLY 1118, as Malmgrenia hartmanae , off Puerto Peñasco, Sonora, Mexico, 31 ◦ 10 ′ N, 113 ◦ 50 ′ W, among lateral chaetae of Aphrodita mexicana , brought up by shrimp trawler, 28 February 1971. coll. R. Brusca, id. J. Kudenov. One syntype ( LACM-AHF POLY 1590) Monterrey County, USA, in tube of Amphitrite or Thelepus , coll. & id. by H.P. Johnson as Polynoe reticulata .

Additional material

One specimen ( LACM – AHF POLY 2462), Punta Cholla Sonora, Mexico, low intertidal, commensal in tubes of Thelepus setosus , coll. S.A. Glassell, 9 May 1941, id. by O. Hartman as Lepidametria gigas .

Description

Holotype complete, with 30 segments ( Figure 6A ), 0.5 cm long, 0.2 cm wide. Prostomium bilobed, as long as wide; lateral and frontal lobes rounded, slightly separated anteriorly ( Figure 5A ); facial tubercle stout, long; two pairs of round eyes, dorsolateral anterior pair on widest part of prostomium, posterior pair partially covered by segment 2. Median antenna ceratophore inserted frontally between prostomial lobes, style subdistally expanded, distally tapering to fine tip; lateral antennae with ceratophores inserted terminally as prolongations of prostomium lobes, styles similar to to median antenna. Palps robust tapering to filiform tips, surfaces with small papillae. Pharynx not everted.

Tentacular segment not visible dorsally; tentaculophores lateral to prostomium, chaetae present; tentacular cirri similar to median antenna. Segment 2 projecting on to prostomium as short nuchal lobe. First pair of elytrophores lateral to prostomium.

Body with 16 pairs of elytrophores on segments 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 28, 30; some elytra missing. Elytra overlapping, covering dorsum, thin, translucent ( Figure 6A ), surfaces with small dots of greyish pigment ( Figure 6B ). First pair of elytra missing. Elytra of anterior and posterior segments without fringe of papillae on margin; surfaces smooth; anterior half of elytra with patch of microtubercles ( Figures 5B , 6B ); posterior half smooth. Microtubercles truncate ( Figure 5C ).

Notopodia shorter than neuropodia ( Figure 5D ). Neuropodia distally truncate with protruding acicular tip, prechaetal lobe with small rounded lobe over acicular tip. Dorsal cirri subdistally expanded and tapering to filiform tips; cirrophores basally expanded; elytrophores wider than dorsal tubercles. Ventral cirri taper to fine tips. Nephridial papilla not visible. Anus dorsal. Pygidium with one pair of anal cirri (one missing in holotype), similar to dorsal cirri.

Notochaetae shorter than neurochaetae; the smaller curved with blunt tips; remaining notochaetae slender, tapering to capillary tips ( Figures 5E , 6C ). Neurochaetae with rows of spines on upper region, bidentate tips, main tooth straight, subdistal tooth shorter than main tooth ( Figures 5F , 6D,E ).

Remarks

The holotype of Halosydna hartmanae may be a juvenile based on the low number of segments. However, the parapodia, chaetae and insertion of elytra correspond to Halosydna . The species was assigned to Malmgrenia and later referred to Halosydna ( Hanley 1987) . I agree with the aforementioned paper because the lateral antennae are inserted terminally (ventrally in Malmgrenia ) and the elytra posterior to pair 12 alternate with one, instead of two dorsal cirri, and the segments 14 and 15 pairs do not alternate with one dorsal cirrus. However, neuropodia are truncate, without prechaetal and postchaetal lobes as in Malmgrenia . Halosydna hartmanae is distinguished by having elytra with smooth margins and smooth surfaces except for microtubercles forming a patch on the anterior half. The non-type material is a 4.5 cm long, 1.0 cm wide specimen, whose elytra from mid-body and posterior segments agree with the species description. Also, it has bidentate neurochaetae and the first and second pairs of elytra with conical, sclerotized microtubercles.

Type locality

Off Puerto Peñasco , Sonora, Mexico (31 ◦ 10 ′ N, 113 ◦ 50 ′ W) .

Distribution

Known from Sonora, Mexico (Puerto Peñasco and Punta Cholla).

Figures

Figure 5. Halosydna hartmanae (Kudenov, 1975). Holotype LACM-AHF POLY 1118. (A) Anterior end, dorsal view; (B) elytron from middle segment; (C) same, microtubercles; (D) parapodium, posterior view; (E) notochaetae; (F) neurochaetae.

Figure 6. Halosydna hartmanae (Kudenov, 1975). Holotype LACM-AHF POLY 1118. (A) Body; (B) elytron from middle segment; (C) notochaeta; (D) neurochaeta; (E) neurochaeta tip.