Prionospio jonatani, Delgado-Blas, Víctor Hugo, 2015

Delgado-Blas, Víctor Hugo, 2015, Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area, Zootaxa 3905 (1), pp. 69-90 : 81-84

Prionospio jonatani sp. nov.

Figures 5 A – F, 6A – J

Prionospio (Prionospio) dubia: Granados-Barba y Solís-Weiss, 1998 :116.

Type material. GULF OF MEXICO. Tabasco: Off the coast of La Venta, E16, 18º39.8'N, 94º13.1'W, 147 m, muddy bottom, holotype (LACM-AHF-POLY 6598), coll. E. Donath Hernández, 10 August 1984; off the coast of La Venta, E12, 18º31'N, 94º36'W, 63 m, 1 paratype (LACM-AHF-POLY 6599), coll. E. Donath Hernández, 10 August 1984; off Paraíso, E20, 18º32.1'N, 93º43.2'W, 38 m; sand, 3 paratypes (LACM-AHF-POLY 6600); Veracruz: between Alvarado and Punta Roca Partida, E7, 18º51'N, 95º41'W, 48 m, muddy, 1 paratype ECOSUR0167, coll. E. Donath Hernández, August 1984; off the coast of Coatzacoalcos, E12, 18º31'N, 94º36'W, 63 m, 1 paratype ECOSUR0168 August 1984; Yucatan: off Alacranes Island, 5 March 2002, E5, 22º21’140’’N, 89º44’970’’W, 1 paratype ECOSUR0169.

Non-type material. GULF OF MEXICO. Campeche: Off Cayo Arcas, E51, 19º59'N, 92º11'W, IMCA II, 188 m, 16.34 ºC, 36.150 ‰, muddy, 1 specimen ( CNAP-ICML, UNAM: PO-09-062), 24 September 1988; in front of Frontera, E76, 19º15'N, 92º28'W, IMCA II, 73 m, muddy, 22.91 ºC, 36.440 ‰, 1.150 % organic matter, 1 specimen ( CNAP-ICML, UNAM: PO-09-062), 27 September 1988; E51, 19º45'N, 91º28'W, Dinamo II, 33 m, 27.8 ºC, 36.49 ‰, muddy, 1 specimen ( CNAP-ICML, UNAM: PO-09-062), 30 November 1990; between Cayo Arcas and Frontera, E65, 19º43'N, 92º10'W, 99 m, 22 ºC, 36.46 ‰, muddy, 1 specimen ( CNAP-ICML, UNAM: PO-09-062), 3 November 1990; E43, IMCA IV, 2 specimens ( CNAP-ICML, UNAM: PO-09-062), 3 October 1989; IMCA II, ( CNAP-ICML, UNAM: PO-09-062), 24 September 1988.

Description. Holotype incomplete, 12 mm long for 44 chaetigers, 0.8 mm wide. Complete paratypes: 16–23 mm long for 72–79 chaetigers, 0.2–0.6 mm wide. Incomplete paratypes: 5–9 mm long for 27–44 chaetigers, 0.4–0.6 mm wide. Color in alcohol opaque white, one specimen brown. Some specimens reproductive, with oocytes present on chaetigers 24–67. Prostomium anteriorly narrow, widening and becoming rounded in midregion ( Fig. 5 A), posteriorly tapered, with short, narrow caruncle extending to the anterior edge of chaetiger 2 and with large V-shaped nuchal organs on either side ( Fig. 5 A). Eyes absent. Palps lost. Peristomium short ( Fig. 6 A), collar-like, surrounding prostomium, fused dorsally with very large, rounded notopodial lamellae on chaetiger 1 ( Fig. 5 A, 6A). Neuropodial postchaetal lamellae of chaetiger 1 small, rounded ( Fig. 5 B, 6A), much smaller than 1/ 3 of the size of the notopodial lamellae.

Four pairs of short branchiae present on chaetigers 2–5 ( Fig. 5 C); first pair longest and thickest, always up to 5 times longer than the fourth pair ( Fig. 5 C, 6A); first pair extending up to chaetiger 6; fourth pair longer than notopodial lamellae ( Fig. 5 C, 6A). Pairs 1 and 4 with long, dense digitiform pinnules, the first pair with pinnules arranged along the outer lateral margin and the fourth pair with pinnules on the posterior face ( Fig. 5 C); pair 4 with fewer pinnules, branchiae with long, naked, smooth distal tips ( Fig. 5 B, C); central stem of branchial pairs 1 and 4 pinnate, elongate; pair 1 multi-segmented, pair 4 smoother (less segmented) and slightly ciliated laterally ( Fig. 5 B, C). Pairs 2 and 3 apinnate, triangular, wide, with short tapered tips, densely ciliated laterally ( Fig. 5 B, C), subequal in length, slightly smaller or larger than notopodial lamellae.

Notopodial postchaetal lamellae of chaetigers 2–4 triangular, slender with wide, rounded bases ( Fig. 5 B, 6B), largest on chaetigers 3–5 with sharp tips; lamellae on chaetigers 6–14 subtriangular with blunt tips ( Fig. 5 B, C, 6C). Subsequent notopodial lamellae rounded ( Fig. 5 D, 6D), small on far posterior chaetigers ( Fig. 6 E). Ventral and dorsal edges of notopodial and neuropodial lamellae not touching on chaetigers 2–4 ( Fig. 5 B, 6A). Notopodial prechaetal lamellae moderate in branchial region, slightly basally fused with notopodial postchaetal lamellae ( Fig.

6B), prechaetal lamellae of chaetiger 9 and subsequent lamellae progressively decreasing in size, split and becoming rounder and smaller ( Fig. 5 D, 6C, D), short on far posterior chaetigers ( Fig. 6 E). Dorsal folds or crests absent ( Fig. 5 C).

Neuropodial postchaetal lamellae on chaetiger 2–7 square, largest on chaetigers 3–4 ( Fig. 5 B); subsequent neuropodial lamellae rounded ( Fig. 5 B, D, 6C, D), smallest on far posterior chaetigers ( Fig. 6 E). Neuropodial prechaetal lamellae very small in branchial region ( Fig. 5 B, 6D, E), rudimentary throughout. Interparapodial pouches lacking.

All capillaries on anterior chaetigers unilimbate, heavily granulated and with long capillary tips ( Fig. 6 F, G); notopodial capillaries of chaetiger 1 arranged in a tuft and neuropodial capillaries of chaetiger 1 arranged in one row, with short, thin chaetae, notopodial chaetae longer ( Fig. 6 F). Notopodial capillaries from chaetiger 2 onwards arranged in three rows, anterior row shorter than posterior rows; chaetae on middle notopodia arranged in two rows ( Fig. 5 D), dorsal chaetae longer than ventral chaetae; thin, smooth chaetae on posterior notopodia arranged in one row. Neuropodial capillaries similar to notopodial capillaries, but shorter and slenderer ( Fig. 6 G), arranged in two rows ( Fig. 5 D) from chaetiger 2 up to chaetiger 16; chaetae on posterior neuropodia arranged in one row. Sabre chaetae in neuropodia from chaetigers 14–18 (holotype 18), one or two per parapodium, robust, long, moderately granulated, without sheaths ( Fig. 6 H). Neuropodial hooded hooks ( Fig. 5 E) from chaetigers 16–28 (holotype 21), up to eight per fascicle, alternating with long, thin capillaries; posterior hooks accompanied by up to three slender, smooth capillaries. Notopodial hooded hooks ( Fig. 6 I) from chaetigers 35–57, up to four per fascicle, alternating with thin capillaries ( Fig. 5 F); all hooks with four pairs of small teeth above main tooth ( Fig. 5 E, 6I) and without secondary hoods ( Fig. 6 I). Neuropodial and notopodial hooks with a large main hood ( Fig. 5 E, F, 6I). The central stem of the hook curved, broken in cross-section, showing the internal nature ( Fig. 5 E).

Pygidium with one long median cirrus and two short lateral lobes ( Fig. 6 J).

Remarks. Prionospio jonatani sp. nov. is very similar to P. dubia Day, 1961 in that both species have the same shaped prostomium, branchiae of the same length, the same shaped anterior notopodial and neuropodial lamellae, granulated anterior chaetae capillaries and hooded hooks without secondary hoods. Prionospio jonatani can be distinguished from the original description of P. dubia Day, 1961 and the descriptions of P. dubia given by Wilson (1990) and Sigvaldadóttir and Mackie (1993), in that the former has a narrower prostomium in the anterior region, the first notopodial lamellae are larger, the notopodial lamellae on chaetigers 6–21 are subtriangular, the notopodial prechaetal lamellae are slightly basally fused with the notopodial postchaetal lamellae in the branchial region, the neuropodial postchaetal lamellae on chaetiger 3 are square, all the capillaries are unilimbate on the anterior chaetae, the sabre chaetae are robust and moderately granulated, and all hooded hooks have four pairs of small teeth above the main tooth. The specimens of Prionospio jonatani examined here also differ from the description given by Maciolek (1985) in that the former have a narrower prostomium in the anterior region, the eyes are absent, the first notopodial lamellae are larger, the neuropodial postchaetal lamellae of chaetiger 1 are rounded, the capillaries of the posterior chaetigers are not striated nor slightly granulated, and neither these capilliaries nor the sabre chaetae have sheaths. Wilson suggested that Maciolek (1985) may have lumped more than one species together in her description of P. dubia , especially given the widespread localities reported for this species (ranging from the Atlantic coast of North America, Surinam, the Mediterranean, the Canary Islands and the Bay of Biscay, Sweden, South Africa) and the depths at which it has been collected (85–2379 m). This is maybe why Maciolek’s (1985) description differs from that of the material from South Africa examined by Wilson (1990), notably in the positions at which the neuropodial sabre chaetae and hooded hooks appear, the shape of the prostomium and the length of the first pair of branchiae. Due to this, and the fact that the P. dubia specimens examined by Maciolek (1985), are widely distributed, Wilson (1990) proposed that the records of this species be verified. The differences between this new species from the other species examined in this study are provided in the key and Table 1.

Etymology. This species is dedicated to the memory of my beloved son Jonatán Iván Delgado Martinez (1993–2014) who left us too soon and so suddenly. My son, Jonatán, was a very cheerful, enthusiastic, passionate, friendly person; a tireless reader, poet, writer, composer, musician and rock drummer. You will always be in our hearts and we miss you immensely my beloved Jona.

Type locality. Southern Gulf of Mexico: Veracruz, Tabasco, Campeche and Yucatán.

Figures

FIGURE 5. Prionospio jonatani sp. nov., non-type (ECOSUR- P 1463: A – F.) SEM micrographs: (A) prostomium, dorsal view; (B) anterior region, lateral view; (C) anterior region, dorsal view; (D) parapodium and chaetae of anterior region; (E) neuropodial hooded hook; (F) notopodial hooded hooks and capillaries. Scale bars: A 66.6 µm; B 100 µm; C 250 µm; D 33.3; E 2.85 µm; F 10 µm.

FIGURE 6. Prionsopio jonatani sp. nov., holotype (LACM-AHF-POLY 000): (A) anterior region, lateral view; (B) notopodium of chaetigers 2 – 3; (C) parapodium of chaetiger 8; (D) parapodium of chaetiger 16; (E) parapodium of posterior fragment; (F) capillary notochaeta of anterior chaetiger; (G) capillary neurochaeta of anterior chaetiger; (H) sabre chaeta; (I) notopodial hooded hook; (J) pygidium, ventral view. Scale bars: A – G 100 µm; H 0.5 µm; I 0.25 µm; J 100 µm.