Terebella turgidula Ehlers, 1887

Londoño-Mesa, Mario H., 2009, Terebellidae (Polychaeta: Terebellida) from the Grand Caribbean region 2320, Zootaxa 2320 (1), pp. 1-93 : 63-64

Terebella turgidula Ehlers, 1887

Figures 18 D-J

Terebella turgidula, Ehlers, 1887:241–245 , Pl. 52. Figs.1–4 .— Treadwell, 1901:198.

(Not Eupolymnia crassicornis, Hessle, 1917:178 .— Augener, 1925:37.— Hartman, 1939:18.— Rullier, 1974:67).

Type material: Holotype MCZ 846 Key West, Florida, US Coast Survey, Gulf of Mexico "Blake Exp. 1877– 78".

Description: Holotype complete, with 140 segments, 210mm long, thorax 52mm long, 23mm wide at segment 5 ( Fig. 18D ). Abdomen 1.4mm wide on segment 30 and 0.4mm wide in the last segment. Body dark brown. Tentacular membrane short, with rounded edge. Eyespots absent. Tentacles dark brown, long. Upper lip short, semi-circular. Lower lip wide, swollen. Fifteen ventral shields, swollen; first shield wide, short, decreasing in width to reduced last shield ( Fig. 18E ). Ventral groove from segment 16 to posterior end, deeper in posterior thoracic region, shallower in abdomen. Three pairs of dichotomous branched branchiae, decreasing in length gradually. Nephridial papillae not seen. Twenty-seven pairs of notopodia. Notochaeta of two lengths ( Fig. 18F ), bilimbate medially, serrated, smoothly oblique distally ( Figs 18G,H ). Limbation wider at base, terminating before oblique region. Thoracic neuropodia wider, swollen; abdominal neuropodia short, narrow and swollen. Uncini ( Figs 18I,J ) MF:3:1–2:1; MF long and stout; Cp with decreasing accessory teeth, teeth on first row as long as one third the MF; Oc convex behind the Cp, and concave in lower region; PP rounded; PF absent; Bs convex; AP projected and rounded, curved downward; AF absent; USr and LSr flattened; SrP short and triangular, near to MF tip; SrA absent. Pygidium smooth and wide.

Discussion: Hessle (1917) indicated that Terebella turgidula could be placed in Polymnia , but without any comment. Later, Augener (1925) considered this species to be a junior synonym of Eupolymnia crassicornis (as Terebella crassicornis Schmarda, 1861 ), because of the type of uncini present. However, T. turgidula has notochaetae distally serrated, while E. crassicornis has smooth-tipped notochaetae, uncini in double rows only in the thorax, and possibly 17 thoracic chaetigers, according to Augener (1925). Therefore, these two species are different and both are valid. On the other hand, Ehlers (1887) described T. turdigula as having 18 thoracic segments with notochaetae, but the type specimen actually has 27 thoracic chaetigers (pers. obs.).

Type locality Key West , Florida, USA .

Distribution: Key West, Florida and Porto Rico.

Figures

FIGURE 1. Uncini types: A. Avicular. B. Pecinate. MF: Main Fang. Sr: Subrostrum. USr: Upper Subrostrum. LSr: Lower Subrostrum. SrP: Subrostral Process. SrA: Subrostral Appendix. AP: Anterior Process. AF: Anterior Filament. Bs: Base. PP: Posterior Process. PF: Posterior Filament. Cp: Capitium. Oc: Occipitium. UOc: Upper Occipitium. LOc: Lower Occipitium.

FIGURE 2. Amaeana sp. 1., (USNM 90555): A. Ventral view. B. Dorsal view. C. Lateral View. D. Anterior ventral shields. E. Abdomen in ventral view. F. Thoracic notopodia from chaetiger 4. G. Fascicle of notochaetae from chaetiger 4. H. Abdominal notopodia from segment 16. I. Abdominal spines from segment 16. J. Pygidium. Scale bars: A,B,C,E: 1.7mm; D: 1.3mm; J: 3.8mm; F,H: 0.4; G: 0.7mm; I: 0.06mm.

FIGURE 3. Biremis blandi (Holotype 47976): A. Ventral view. B. Dorsal view. C. Anterior end in dorsal view. D.Anterior end in ventral view. E-F. Nephridial papillae. G. Neuropodia. H. Neuropodium from segment 16. I. Uncinus segment from 16. J. Abdomen in dorsal view and pygidium. Scale bars: A,B: 12mm; C,D: 9mm; E,F: 3.1mm; G: 1.3mm; H: 0.2mm; I: 0.02mm.

FIGURE 4. Enoplobranchus sanguineus (Syntype YPM 8909): A. Dorsal view. B. Anterior end in dorsal view. C. Anterior end in ventral view. D. Ventral view. E. Lateral view. F. Thoracic notopodia from segment 4. G. Notopodia from segment 5. H. Notopodia from mid-thoracic region. I. Abdominal notopodia. Scale bars: A,D,E: 5.5mm; B,C: 2.7mm; F: 0.4mm; G: 0.5mm; H: 0.5mm; I: 0.6mm.

FIGURE 18. Scionides reticulata (Holotype MCZ 840): A. Thoracic region in ventral view. B. Middle region in ventral view. C. Posterior end in lateral view. Terebella turgidula (Holotype MCZ 846): D. Complete specimen. E. Anterior thoracic region in ventral view. F. Fascicle of notochaetae from anterior thoracic region. G. Long notochaeta from anterior thoracic region. H. Short notochaeta from anterior thoracic region. I. Uncinus from anterior thoracic region. J. Uncini in double rows from mid-thoracic region. Scale bars: A,B,C: 2.8mm; D: 23mm; E: 1.5mm; F: 0.4mm; G,H: 0.07mm; I,J: 0.05mm.