Prionospio crassumbranchiata , 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: 73-76
treatment provided by
Prionospio crassumbranchiata sp. nov.
Figures 2View FIGURE 2 A – F, 3 A – L
Material examined. GULF OF MEXICO. Veracruz: Off the coast of Coatzacoalcos, E11, 18º 44 'N 94 º 41.9 'W; 173 m, muddy, 8 August 1984, coll. E. Donath Hernández, holotype (LACM-AHF-POLY 6597); Tabasco: Off the coast of Paraiso, E7, 18º 30 'N, 93 º 36 'W, IMCA II, 29 m, 27.2 ºC, 36.1 ‰, org. carb. 0.120 %, muddy-sand, 1 paratype ( CNAP-ICML, UNAM: POP-09-002); Campeche: Off Cayo Arcas, E51, 19º 59 'N, 92 º 11 'W, IMCA II, 188 m, 16.3 ºC, 36.2 ‰, muddy, 24 September 1988, 2 paratypes ( CNAP-ICML, UNAM: POP-09-002); off Cayo Arcas, E51, 19º 59 'N, 92 º 11 'W, 188 m, 16.3 ºC, 36.2 ‰, muddy, 24 September 1988, 1 paratype ( CNAP-ICML, UNAM: POP-09-002).
Description. Holotype incomplete, 9.0 mm long; consists of one fragment with 30 chaetigers, 1.2 mm wide. Paratypes incomplete 6.6–9.1 mm long, with 28–34 chaetigers, 1.2–1.3 mm wide. Color in alcohol pale white. Prostomium bottle-shaped, truncate on anterior margin ( Fig. 2View FIGURE 2 A, 3 A), posteriorly tapered, with short, narrow caruncle extending to the anterior edge of chaetiger 2 ( Fig. 2View FIGURE 2 A, 3 A) with large triangular nuchal organs on either side ( Fig. 2View FIGURE 2 A, 3 A). Eyes absent ( Fig. 3View FIGURE 3 A). One paratype with two pairs of subdermal brown eyes arranged in a trapezoid; anterior pair crescent-shaped; posterior pair small, rounded. Palps lost, except in one specimen with a pair of palps inserted anterior to the nuchal organs: the left palp in the process of regeneration and the right palp fragmented and in bad condition, with a short basal sheath ( Fig. 2View FIGURE 2 A –C). Peristomium long, collar-like, surrounding the prostomium, laterally separate ( Fig. 2View FIGURE 2 B), partially fused dorsally with very large rounded notopodial lamellae on chaetiger 1 ( Fig. 3View FIGURE 3 A). Neuropodial postchaetal lamellae of chaetiger 1 very large and rounded ( Fig. 2View FIGURE 2 B), smaller than notopodial lamellae.
Four pairs of short branchiae present on chaetigers 2–5, the first pair longest and thickest ( Fig. 3View FIGURE 3 A); sometimes the first and fourth pairs equal in length. First pair with long, dense digitiform pinnules on the lateral and posterior faces, and with short naked, smooth distal tips; distribution of the pinnules basally to distally: all pinnules arranged in curved rows ( Fig. 3View FIGURE 3 B, C), in the basal and middle regions with up to 7 pinnules per row ( Fig. 3View FIGURE 3 C) and in the distal region with 3 pinnules per row; the central stem of branchial pair 1 pinnate, cylindrical, very thick and with a blunt tip ( Fig. 3View FIGURE 3 A). Pairs 2–4 apinnate; pairs 2 and 3 triangular, broad ( Fig. 2View FIGURE 2 A, 3 A), densely ciliated laterally, with short, sharp tips; subequal in length to the notopodial lamellae, shorter than pinnate pair. Pair 4 cirriform ( Fig. 2View FIGURE 2 A), basally united by a short, low dorsal fold; subequal or longer than notopodial lamellae.
Notopodial postchaetal lamellae triangular with triangular tips widest on chaetigers 2–6 ( Fig. 2View FIGURE 2 A); largest on chaetigers 3–5; lamellae of chaetigers 7–10 subtriangular ( Fig. 2View FIGURE 2 C). Lamellae gradually becoming smaller, rounder and more dorsally directed from chaetigers 15–16 ( Fig. 2View FIGURE 2 C, D); lamellae of posterior chaetigers rounded ( Fig. 3View FIGURE 3 D).
Notopodial postchaetal lamellae united, forming low dorsal crests from chaetigers 5–6 ( Fig. 2View FIGURE 2 A, 3 A), and continuing as very low folds up to about chaetiger 23–31 ( Fig. 2View FIGURE 2 C, D). Ventral and dorsal edges of notopodial and neuropodial lamellae not touching on anterior chaetigers ( Fig. 2View FIGURE 2 D). Notopodial prechaetal lamellae moderately sized in the branchial region, not fused basally with the notopodial postchaetal lamellae, posterior chaetigers rudimentary.
Anterior neuropodial postchaetal lamellae large, rectangular with rounded edges ( Fig. 2View FIGURE 2 B); more angular and dorsally directed on chaetigers 3–4 ( Fig. 3View FIGURE 3 E); rectangular, slightly more slender and ventrally directed on chaetigers 5–6 ( Fig. 3View FIGURE 3 F); subsequent neuropodial lamellae rounded ( Fig. 2View FIGURE 2 D, E, 3 G, H,) and small on far posterior chaetigers. Neuropodial prechaetal lamellae small in branchial region ( Fig. 2View FIGURE 2 B), rudimentary throughout. Interparapodial pouches on chaetigers 4–20 / 21 non-reticulated ( Fig. 2View FIGURE 2 D, E).
All capillaries on anterior chaetigers alimbate, thin, granulated ( Fig. 3View FIGURE 3 I, J); notopodial and neuropodial capillaries of chaetiger 1 arranged in two rows, with short, thin chaetae; notopodial chaetae longer ( Fig. 3View FIGURE 3 I). Notopodial capillaries of chaetigers 2–11 arranged in three rows, anterior row shorter than posterior rows; middle notopodial capillaries granulated, arranged in two rows of chaetae, dorsal chaetae very long and acute ( Fig. 3View FIGURE 3 I), ventral chaetae very short and acute; neuropodial capillaries in two rows, chaetae very long, acute, granulated ( Fig. 3View FIGURE 3 J), first row much shorter; posterior capillaries thin and smooth. Sabre chaetae in neuropodia from chaetiger 19–20, up to three per parapodium ( Fig. 2View FIGURE 2 F), each chaeta stout, faintly granulated distally, with slightly limbate tips, long ( Fig. 3View FIGURE 3 K). Neuropodial hooded hooks ( Fig. 3View FIGURE 3 L) from chaetigers 20, up to 13 per fascicle, accompanied by up to 10 capillaries; all hooks with six pairs of small teeth ( Fig. 3View FIGURE 3 L) above small main tooth; hooks appear to possess very striated secondary hoods, producing a feathered effect below the main fang ( Fig. 3View FIGURE 3 L); neuropodial hooks with large principal hood, ventral hooks shorter than the dorsal hooks ( Fig. 2View FIGURE 2 F). Notopodial hooded hooks not observed up to chaetiger 34.
Pygidium not known.
Remarks. Prionospio crassumbranchiata sp. nov. is closely related to P. ehlersi Fauvel, 1928 and P. saccifera Mackie & Hartley, 1990 in that it has the same shaped prostomium, branchial arrangement, presence of interparapodial pouches and structure of hooded hooks. However, Prionospio crassumbranchiata sp. nov. can be distinguished from the original description of P. ehlersi Fauvel, 1928 , and the redescription of P. ehlersi by Mackie & Hartley (1990) and P. saccifera in that in P. crassumbranchiata , the peristomium is laterally separate, but partially fused dorsally with the first chaetiger; the first pair of branchiae have long, dense, digitiform pinnules on their lateral and posterior faces; the neuropodial lamellae of chaetiger 2–5 are rectangular, more angular, and dorsally directed; the neuropodial prechaetal lamellae on the middle chaetigers are short; all the capillaries on the anterior chaetigers are alimbate; the sabre chaetae have slightly limbate tips; all hooks have six pairs of small teeth above the main tooth and the sabre chaetae start on chaetiger 20. P. crassumbranchiata differs from P. saccifera in that the notopodial lamellae of chaetiger 1 are rounded; the first branchial pair is not united basally by a short, low dorsal crest; the interparapodial pouches start on chaetigers 4; branchial pairs 2–3 are apinnate, triangular, shorter, with short sharp tips. Prionospio crassumbranchiata sp. nov. also differs from the redescription of P. ehlersi by Maciolek (1985) in that the former has a bottle-shaped, anteriorly truncate prostomium; no eyes; low dorsal folds; rectangular anterior neuropodial postchaetal lamellae with rounded edges, more angular and dorsally directed on chaetigers 3–4, rectangular, slightly more slender and ventrally directed on chaetigers 5–6 and interparapodial pouches from chaetiger 4. Whereas, the specimens described by Maciolek have a rectangular prostomium that is narrower in the middle region and broadly rounded anteriorly ( Maciolek, 1985: 345: Fig, 7); they also have the presence of eyes; a high dorsal crest; rounded neuropodial lamellae and interparapodial pouches starting from chaetigers 2–5 making them different from P. crassumbranchiata sp. nov. The differences between this new species and the other species examined are provided in the key and table 1.
Type locality. South of the Gulf of Mexico: Veracruz, Tabasco and Campeche.
Etymology. The specific name is from the Latin crassum meaning thick and refers to the thickness of the first pairs of branchiae.
sp. nov. 1971; Maciolek 1985 nov. , this paper ()
Measurement (mm): Anterior fragment: Anterior fragments: a. 7.1 [6, 0.3] (12.0– a. 16–23, 0.2–0.6 a. 4.5-5.2, 0.2–0.3 a. 5.0– 5.5, 0.2
Length, width a. 17, 1.0 a. 6.6–9.1, 1.2-1.3 14.0, 0.4–0.5) b. 72–79 b. 38–40 b. 45–49
No. of chaetigers b. 51 b. 28–34 b. 33  (59–65)
Prostomium Bottle-shaped, Bottle-shaped, Subtriangular, Skittle-shaped, Square-shaped, Pyriform-shaped, anteriorly trucante, anteriorly truncate anteriorly rounded anteriorly narrow, anteriorly truncate anteriorly rounded with a small medial rounded
pairs of eyes a. Crescent-shaped Absent or a. Rounded Absent a. Cup-shaped Absence or
Anterior pair b. Large eyespots a. Crescent-shaped b. Crescent-shaped b. Cup-shaped a. Rounded
Posterior pair b. Rounded b. Cup-shaped
Caruncle Long, narrow Short, narrow Short, blunt Short, narrow Short, blunt and Long, blunt prominent, with a middle slit along caruncle
Shape of nuchal Absent (not observed) Triangular; on both (Long; on both sides Large, V-shaped; on Long and wide; on Fused over both sides
organs; position sides of caruncle of caruncle) [may both sides of caruncle both sides of caruncle of caruncle
respect to the caruncle extend across
Peristomium Moderate Long Short Short Short Moderate
Relative length of 1> 4 1>, = 4 1>, = 4 1> 4 1>, = 4 1> 4
pinnate branchial pairs
Shape of apinnate Triangular, broad Triangular, broad Cirriform Triangular, broad Triangular, narrow Cirriform
branchial pairs 2 and 3
Notopodial postchaetal Rounded, large Rounded, very large Rounded, large Rounded, very large Rounded, moderate Rounded, large
lamellae (chaetiger 1)
Notopodial and Touching chaetiger 3 Not touching anterior (Not overlapping or Not overlapping or Not touching anterior Not overlapping or
neuropodial lamellae chaetigers touching) touching chaetigers touching overlaps or
High dorsal crests a. Absent a. 5–6 a. 7–9 a. Absent a. 7 & 8 a. 7
Low dorsal folds b. 6–11 b. 7–23 / 31 b. 10–11 b. Absent b. 9–14 b. Absent
sp. nov. 1971; Maciolek 1985 nov. , this paper ()
Anterior notopodial Very large on Moderate Large in branchial Moderate in branchial Low Very low
prechaetal lamellae chaetigers 2-7 region region
Anterior neuropodial a. Subtriangular, a. Rectangular, more a. Rounded [squarish] a. Square a. Subtriangular, a. Subtriangular,
postchaetal lamellae ventrally pointed angular, dorsally b. Angled, trapezoid, b. Square ventrally pointed ventrally pointed Chaetiger 2 b. Subtriangular, directed dorsally directed c. Square b. Subtriangular, b. Trapezoid, slightly Chaetiger 3 ventrally pointed b. Same as above [squarish] d. Square ventrally pointed dorsally pointed Chaetiger 4 c. Oval c. Same as above c. Rounded [squarish] c. Rounded c. Rounded Chaetiger 5 d. Oval d. Same as above d. Rounded d. Rounded d. Rounded [squarish]
Anterior neuropodial Large Low Moderate Very low Low Very low
Interparapodial Absent Present Absent Absent Absent Absent
Anterior notopodial Thicker, alimbate, Alimbate [Bilimbate]and Unilimbate, with very Slightly unilimbate Very long and very
chaetae with very long unilimbate (Very long capillary tips acute, unilimbate
capillary tips long and very acute,
Anterior neuropodial Thick, alimbate, with Alimbate [Bilimbate] Unilimbate Alimbate Short and very acute,
chaetae very long capillary (unilimbate, very alimbate tips long and very acute)
Sabrechaetae 10 19–20 10 14–18 10 10
Neuropodial hooded a. 16 a. 20 a. 11–12 [10–13] a. 16–28 a. 12–14 a. 11–12
hooks b. 4 b. 6 (12–13) b. 4 b. 4 b. 4 Start on chaetiger c. Absent c. Very striated b. 4 c. Absent c. Conspicuous c. Conspicuous No. of pairs of c. Conspicuous
Notopodial hooded a. 46? a. 21–37 (26–34) a. 35–77 a. 23–39 a. 28–32
hooks b. 4 b. 4 b. 4 b. 4 b. 4 Start on chaetiger c. Absent c. Conspicuous c. Absent c. Conspicuous c. Conspicuous No. of pairs of
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