Table 1 Some taxonomic characteristics of seven species of Prionospio
Characters | P. heterobranchia | P. newportensis | P. spongicola | P. texana | P. rosariae | P. caribensis | P. jamaicensis |
|---|---|---|---|---|---|---|---|
a. Measurement (mm): a. length, width b. No. of chaetigers | a. 6–22, 0.25–1 b. 46–69 | a. 22, 1.0 b. 91 | Anterior fragment: a. 4, 0.3 b. 30 | Anterior fragment: a. 12, 0.7 b. 57 | a. 4–9, 0.4–0.7 b. 38–65 | a. 11.5–15, 0.6–0.8 b. 54–70 | a. 5.5–12, 0.25–0.6 b. 44–70 |
Prostomium | Triangular-shaped, anteriorly rounded | Triangular-shaped, anteriorly rounded with small medial peak | Bottle-shaped, anteriorly rounded | Bottle-shaped, anteriorly truncate | Triangular-shaped, broadly rounded anteriorly, with a slightly central notch | Bottle-shaped, anteriorly rounded | Triangular-shaped, anteriorly rounded |
Two pairs of eyes a. Anterior pair b. Posterior pair | a. Cup-shaped b. Cup-shaped | a. Rounded b. Crescent-shaped | a. Rounded b. Rectangular | a. Crescent-shaped b. Oval | a. Crescent-shaped b. T-shaped | a. Crescent-shaped b. Oval | a. Crescent-shaped b. Oval with inner anterior projection |
Peristomium | Short | Short | Long | Short | Short | Moderate | Long |
Pinnate branchial pairs 1, 4 and 5 a. Relative length b. Central stem of the branchiae | a. 1 > 4, 5, sometimes 1 = 5 > 4 b. Pairs 1 and 5 elongate, pair 4 triangular | a. 1 > 4, 5 b. Pairs 1, 4 and 5 elongate | a. 1 lost, 4 < 5 b. Pairs 1, 4 and 5 elongate | a. 1 = 5 > 4 b. Pairs 1, 4 and 5 elongate | a. 1 = 5 > 4 b. Pairs 1, 4 and 5 elongate | a. 1 > 4 = 5, sometimes  = 4, 5 b. Pairs 1, 4 and 5 elongate | a. 1 > , =5 > 4 b. Pairs 1, 4 and 5 elongate |
Shape of apinnate branchial pairs 2 and 3 | Triangular | Triangular | Triangular | Triangular thin | Subtriangular | Triangular | Cirriform |
Notopodial postchaetal lamellae (chaetiger 1) | Rounded, small | Rounded, big | Rounded, big | Rounded, big | Rounded, big | Rounded, big | Rounded, very big |
Notopodial and neuropodial lamellae with overlaps or touching | Touching chaetigers 3–5 | Overlaps chaetigers 2–8 | Touching chaetiger 3 | Overlaps chaetigers 2–4 | Not overlapping or touching | Overlaps chaetigers 2–4 | Overlaps chaetiger 2–4 |
Dorsal crest or folds | More conspicuous on chaetigers 7–11 | Absent | Absent | Absent | Absent | Chaetigers 7–15 | Absent |
Anterior notopodial prechaetal lamellae | Very big, on chaetigers 2–12 | On chaetigers 2–7 | Very low | Moderate | Low | Very big, on chaetigers 2–16 | Moderate |
Anterior neuropodial postchaetal lamellae a. Chaetiger 2 b. Chaetiger 3 c. Chaetiger 4 d. Chaetiger 5 | a. Rounded b. Rounded c. Rounded d. Rounded | a. Rounded b. Subtriangular c. Oval d. Rounded | a. Rhomboid b. Rounded c. Rounded d. Triangular | a. Rounded b. Rounded c. Rounded d. Rounded | a. Subrectangular, with dorsally directed process, the lower corner rounded b. Rounded c. Rounded d. Rounded | a. Rounded b. Square c. Rounded d. Rounded | a. Square, erect b. Square c. Rounded d. Rounded |
Anterior neuropodial prechaetal lamellae | Big | Big | Very low | Low | Very low | Very low | Very low |
a. Anterior notopodial chaetae b. Middle notopodial chaetae | a. Granulated, lightly striated b. Same as anterior chaetae | a. Anterior row clear, posterior row with granulations b. Without granulations | a. Without granulations b. Same as anterior chaetae | a. Granulated b. Without granulation | a. Granulated b. Same as anterior chaetae | a. Without granulations b. Same as anterior chaetae | a. Without granulations b. With granulations |
Anterior neuropodial chaetae | Granulated, lightly striated | Without granulations | Without granulations | Without granulations | With granulations | Without granulations | Without granulations |
Sabre chaetae a. Start chaetiger b. Description of chaetae | a. 13–15 b. Lightly granulated, without sheath | a. 16 b. Distinctly granulated, without sheath | a. 11 b. Moderate granulated, without sheath | a. 14 b. Heavily granulated, striated basally, with sheath | a. 12–13 b. Distally granulated, with long tip | a. 14–15 b. Robust, very long, heavy granulated, with long tip, without sheath | a. 12–14 b. Stout, curved, heavy granulated, with sheath |
Neuropodial hooded hooks a. Start chaetiger b. No. of pairs of accessory teeth c. Secondary hood | a. 13–15 b. 4 c. Conspicuous | a. 14 b. 4 c. Absent | a. 12 b. 2–3, first pair almost same size as main tooth c. Small | a. 14 b. 4 c. Small, primary hood below secondary hood slightly striated | a. 12–14 b. 4 c. Small | a. 14–15 b. 4 c. Small. | a. 12–14 b. 3 c. Small |
Notopodial hooded hooks a. Start chaetiger b. No. of pairs of accessory teeth c. Secondary hood | a. 32–40 b. 4 c. Conspicuous | a. 54 b. 4 c. Absent | ? | a. 48 b. 4 c. Small | a. 23–39 b. 4 c. Small | a. 32–44 b. 4 c. Small | a. 27–48 b. 3 c. Small |