Pelogenia brevipalpata, Cruz-Gómez, 2022
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Pelogenia brevipalpata sp. nov.
A species of Pelogenia with short palps, barely reaching segments 3–4; middorsal lobe of segment II absent; neurochaetae from segment II with smooth basal surface; neurochaetae from posterior segment with blades long; papillate medial processes in posterior elytra.
The specific name of the species brevipalpata is a combination of the Latin singular adjective ‘ brevis (-es)’, meaning ‘short’, and the noun ‘ palpus (-i)’, adding the suffix ‘ -ata ’, meaning ‘having tentacles or tentacled’. The name indicates that the palps are very short, and it is feminine to match the generic gender ( ICZN 1999, Art. 31.2).
Paratype MEXICO • 1 incomplete spec., 52 segments, 0.9 cm long, 0.6 cm to segment 30, 0.6 cm wide; Quintana Roo, Punta Herradura ; 18°32′23″ N, 87°44′32″ W; depth 2 m; 28 October 1997; S.I. Salazar-Vallejo and L.F. Carrera-Parra leg; dead coral; ECOSUR 290 View Materials GoogleMaps .
BODY. Pale orange, long, broad ( Fig. 13A View Fig ); 120 segments, 3.2 cm long, 0.8 cm to segment 30, 3.2 cm wide. Middorsal line covered with white foreign particles attached to adhesive papillae ( Fig. 13B View Fig ), and only one damaged elytron remaining attached to the body; paratype with no remaining elytra. Venter covered only with large globular papillae ( Fig. 13C View Fig ).
PROSTOMIUM. Oval, wider than long. Two pairs of eyes, anterior eyes larger, inserted anteriorly. Lateral antennae short, slender; ceratophores short, styles as long as ceratophores, dorsally fused with tentacular segment, partially covered by median antennal ceratophore ( Fig. 13D–E View Fig ). Median antenna with bulbous ceratophore, slightly longer than prostomium, with a longitudinal ridge; style very slender, short, as
long as prostomium ( Fig. 13D View Fig ). Middorsal lobe of segment II absent. First segment directed anteriorly, fused with tentacular segment; biramous, chaetae simple verticillate. Dorsal tentacular cirrus longer than neuropodia including chaetae, ventral tentacular cirrus as long as dorsal tentacular cirrus; palps short reaching segment three, with inner palpal sheaths, left palp missing ( Fig. 13C View Fig ).
ELYTRA. Only one posterior elytron was found. Damaged posterior right elytron oval, with three posterior processes, anteriorly notched ( Fig. 14A View Fig ); surface with flat papillae, marginal papillae short and long dendritic ( Fig. 14G View Fig ).
RIGHT PARAPODIUM FROM SEGMENT II ( Fig. 13G View Fig ). Notopodia conical, smooth (non-papillate), short, as long as neuropodia; notopodial flange smooth (non-papillate), small. With up to 100 simple verticillate notochaetae, tips hooked, shortest ones ⅓ as long as notopodia; longest ones 3 × as long ( Fig. 13H View Fig ).
Neuropodia truncated, smooth (non-papillate), with a truncated lobe ( Fig. 13G View Fig ). Neurochaetae falcigers and spinigers; all blades entire with hooked tips, but in units C and D, tapered: unit A, six falcigers with handles slender, covered by transverse rows of spines, blades long, 10 × as long as wide ( Fig. 13I View Fig ); unit B, four neurochaetae with handles thick, covered by transverse rows of spines, blades lost ( Fig. 13J View Fig ); units C and D undifferentiated, one spiniger with handle slender, covered by transverse rows of spines, blade long, 13× as long as wide ( Fig. 13K View Fig ).
RIGHT PARAPODIUM FROM SEGMENT III ( Fig. 13L View Fig ). Dorsal cirrophore as long as cirrostyle ( Fig. 13F View Fig ). Notopodia conical, smooth (non-papillate), short, slightly shorter than neuropodia; notopodial flange rounded. With up to 30 simple verticillate notochaetae, tips hooked, shortest ones twice as long as notopodia, longest ones 3 × as long ( Fig. 13M View Fig ). Neuropodia conical, papillate, short ( Fig. 13L View Fig ). Neurochaetae only falcigers; blades entire, slightly falcate: unit A, one neurochaeta with handle slender with 9 transverse rows of spines, blade lost ( Fig. 13N View Fig ); unit B, four neurochaetae with handles thick with 7–9 transverse rows of spines, blade lost ( Fig. 13O View Fig ); unit C, three falcigers with handles slender with 8–12 transverse rows of spines, blades long, 10× as long as wide ( Fig. 13P View Fig ); unit D, four falcigers with handles slender with 13–15 transverse row of spines, blades long, 9–10 × as long as wide ( Fig. 13Q View Fig ).
RIGHT PARAPODIUM FROM SEGMENT 28 (MIDDLE SEGMENT) ( Figs 13R View Fig , 14B View Fig ). Notopodia conical, short, smooth (non-papillate), half as long as neuropodia. With up to 80 simple verticillate notochaetae, tips hooked, shortest ones twice as long as notopodia, longest ones 3× as long ( Figs 13S View Fig , 14C View Fig ). Neuropodia conical, papillate. Neurochaetae only falcigers; all blades entire, falcate: unit A, three falcigers, handles thick with transverse rows of denticles, blades medium-sized, 6 × as long as wide ( Figs 13T View Fig , 14D View Fig ); unit B, three falcigers with handles thick with barely perceptible transverse rows of denticles, blades medium-sized, 5× as long as wide ( Fig. 13U View Fig ); unit C, two falcigers with handles slender, smooth, blades medium-sized, 6–7 × as long as wide ( Figs 13V View Fig , 14E View Fig ); subunit 1, four falcigers with handles thick with barely seen transverse rows of denticles, blades short, 3–4× as long as wide ( Figs 13W View Fig , 14E View Fig ); unit D, four falcigers with handles slender, smooth, blades long, 14–16× as long as wide ( Figs 13X View Fig , 14F View Fig ).
PYGIDIUM. Rounded with two anal cirri ( Fig. 14H View Fig ).
Pelogenia brevipalpata sp. nov. is grouped with other species that have posterior elytra with papillate medial processes and some posterior processes, such as P. arenosa delle Chiaje, 1830, P. fimbriata ( Hartman, 1939) , and P. kinbergi ( Hansen, 1882) . However, P. brevipalpata sp. nov. differs from these three species in having short palps barely reaching segment 4 and lacking a middorsal lobe on segment II. Well-preserved specimens might enhance the morphological details of the species, regarding elytra and neurochaetae from anterior segments.
Caribbean Sea. Quintana Roo, Mexico.
Departamento de Geologia, Universidad de Chile
Tavera, Department of Geology and Geophysics
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