Autolytus cognettii, Çinar & Gambi, 2005

Çinar, Melih Ertan & Gambi, Maria Cristina, 2005, Cognetti’s syllid collection (Polychaeta: Syllidae) deposited at the Museum of the Stazione Zoologica ‘‘ Anton Dohrn’ ’ (Naples, Italy), with descriptions of two new species of Autolytus, Journal of Natural History 39 (10), pp. 725-762 : 730-738

Autolytus cognettii sp. nov.

( Figure 3 ) Langerhans 1879, p 580–581,

Plate 33, Figure 32 (non

Material examined

SZN-POL1, Holotype, Station 1, Lago Fusaro, 12 January 1955, on algae, 0–1 m, coll. Cognetti.

Description

Specimen complete, 4 mm long, 0.22 mm wide, H+ 1051.06 mm, for 35 chaetigers, yellowish. Prostomium rounded, wider than long, with two pairs of dark reddish eyes; anterior pairs larger and with lenses; one pair of ocular specks located on anterior margin of prostomium ( Figure 3A ). Median antenna originating between anterior eyes, extending to chaetiger 18; lateral ones inserted in front of ocular specks, reaching chaetiger 7. Palps small, visible dorsally. Nuchal epaulettes distinct, reaching anterior margin of chaetiger 2. Peristomium narrow dorsally, with two pairs of tentacular cirri; dorsal ones two times longer than ventral ones, extending to chaetiger 8. Dorsal cirri on chaetiger 1 very long, subsequent ones longer than body width; cirrophores of all dorsal cirri less developed; shorter than parapodial lobes. Parapodia subtriangular. Falcigers numbering 10 and seven on anterior and posterior parapodia, respectively; shafts coarsely serrated at tip; blades bidentate; proximal tooth longer and thicker than distal one ( Figure 3C ); blades of superior falcigers 7.5 Mm long; those of inferior ones 10 Mm long throughout. Dorsal simple chaeta bayonet-shaped, from chaetiger 3, subdistally serrated ( Figure 3D ). Acicula numbering one throughout, thin, tapering. Proventricle 0.30 mm long, 0.18 mm wide, extending ca three segments, with 35 muscle cell rows. Pharynx between chaetigers 1 and 7, with one sinuation; trepan with a total of 30 teeth, arranged as four large, sharp, triangular teeth separated by seven to nine small, relatively blunt teeth ( Figure 3B ). Pygidium with two long anal cirri ( Figure 3A ).

Remarks

Autolytus cognettii sp. nov., which was labelled as A. benazzii Cognetti, 1953 by Cognetti, differs from A. benazzii in the morphology of the trepan (trepan with equal teeth in A. benazzii , trepan with unequal teeth in A. cognettii ); length of dorsal cirri (much longer in A. cognettii ) and cirrophores (much smaller in A. cognettii ); length of median antenna (longer in A. cognettii ). The figure of the trepan of the Madeira specimen (Plate 33, Figure 32), which was identified as Proceraea brachycephala Marenzeller, 1874 by Langerhans (1879), seems to be identical to that of A. cognettii . Langerhans (1879) also pointed out the difference between his specimen and Autolytus brachycephalus : ‘‘Pharynx mit 30 Zähnen; bei meinem Exemplar waren nur drei davon grösser, bei Marenzeller’s wohl 8–10’’. Gidholm (1966) then considered the Langerhans’s record of A. brachycephalus as a synonym of A. langerhansi Gidholm, 1966 , which is characterized by having cirrophores longer than parapodial lobes; a trepan consisting of 29–42 unequal teeth separated by three, four and five larger ones; well-developed infradental spines, and relatively large eyes. Autolytus cognettii seems to be similar to A. langerhansi , but differs from it by a number of characters; cirrophores (smaller than parapodial lobes in A. cognettii ); median antenna (smaller in A. cognettii ); nature of small teeth of the trepan (rectangular with pointed tip in A. cognettii , sharp and triangular in A. langerhansi ); nature of large teeth of trepan (associated with small teeth in A. langerhansi ; not associated in A. cognettii ); and location of pharynx (between chaetigers 1 and 7 in A. cognettii , between chaetigers 3 and 8 in A. langerhansi ).

Etymology

The species is named after Professor Guiseppe Cognetti in honour of his contributions to the taxonomy of Syllidae and ecology of polychaetes in the Mediterranean Sea.

Distribution

Madeira? ( Langerhans 1879) and Lago Fusaro (Gulf of Naples, Mediterranean Sea).

Autolytus convolutus Cognetti, 1953

( Figure 4 )

Autolytus convolutus Cognetti 1953a, p 323 , Figures 1 , 2 ; Cognetti 1957, p 71, 72, Figure 15;? Ben-Eliahu 1977a, p 85 –86, Figure 12; San Martín 1984, p 413–415, Figure 111; Pascual and Núñez 1999, p 83 –85, Figure 5 a–e . Autolytus (Regulatus) convolutus: Imajima 1966, p 47 –49, Figure 12.

Material examined

SZN-POL2, Lectotype, Station 6, via Caracciolo, 18 October 1953, algae, 0–2 m, coll. Cognetti.

Description

Specimen complete, 2.4 mm long, 0.12 mm wide, H+ 1050.72 mm, 41 chaetigers, pale yellowish. Prostomium oval, with two pairs of eyes in trapezoidal arrangement; anterior ones larger, without ocular specks ( Figure 4A ). Palps small, completely fused to each other. Median antenna originating between anterior eyes, extending to chaetiger 6; lateral ones emerging from anterior margin of prostomium, reaching chaetiger 4. Peristomium distinct on dorsal side, with two pairs of tentacular cirri; dorsal ones longer, extending to chaetiger 5; ventral ones shorter, reaching chaetiger 3. Nuchal epaulettes reaching middle region of chaetiger 1. Dorsal cirri on chaetiger 1 reaching chaetiger 6. Except for dorsal cirri on chaetiger 2, remaining dorsal cirri shorter than body width, with less-developed cirrophores; shorter than parapodial lobes. Antennae, tentacular cirri and dorsal cirri on chaetigers 1 and 2 thicker than the rest; all having small, numerous inclusions within all the appendages; scarcely present within parapodia and dorsum of body. Parapodia, particularly in middle region of body, very thick, triangular in shape and with somewhat pointed tips. Falcigers on anterior parapodia numbering six, bidentate; proximal tooth thicker and longer than distal one ( Figure 4C ); superior falcigers with blades 5 Mm long and inferior ones with blades 7.5 Mm long. Shafts of falcigers with tips coarsely serrated. Posterior parapodia with six falcigers, morphologically similar to those on anterior ones. Dorsal bayonet chaeta from chaetiger 1, slightly curved, with minute spines on tip ( Figure 4D ). Proventricle 0.17 mm long, 0.11 mm wide, extending ca 2.5 segments, with 24 muscle cell rows. Pharynx with many sinuations, between chaetigers 3 and 7, with trepan consisting of nine equal, triangular, large teeth. Pygidium rectangular, with two small anal cirri.

Remarks

The report of Autolytus convolutus in the Red Sea and the Eastern Mediterranean by Ben- Eliahu (1977a) seems to be questionable as Ben-Eliahu’s specimens have ocular specks on the prostomium (absent in Cognetti’s specimen) and longer proventricle (occupying three segments in Ben-Eliahu’s specimens versus two segments in Cognetti’s specimen). Ben- Eliahu (1972) also reported this species from the Suez Canal with six eyes.

Distribution

Western Mediterranean ( Cognetti 1953a; San Martín 1984), Eastern Mediterranean (? Ben-Eliahu 1977a; Çınar and Ergen 2002),?Red Sea (Gulf of Elat and Suez Canal) ( Ben-Eliahu 1972), Eastern Atlantic (Canary Islands) ( Pascual and Núñez 1999), Sea of Japan ( Imajima 1966).

Autolytus mediterraneus (Cognetti, 1953) comb. nov.

( Figure 5 )

Autolytus lugens mediterraneus Cognetti 1953b, p 123 –125, Figure 1 .

Material examined

SZN-POL3, Lectotype, Station 3, Secca della Gajola, on coralligenous substrata, 40 m, coll. Cognetti.

Description

Specimen complete, 2.13 mm long, 0.15 mm wide, H+ 1050.63 mm, for 24 chaetigers, without colour marking, with small and large inclusions on dorsum of body. Prostomium oval, with small ridges near anterior margin, wider than long; with two pairs of reddish eyes, anterior ones larger; with ocular specks ( Figure 5A ). Palps small, visible dorsally. Median antenna originating between anterior eyes, extending to chaetiger 9; lateral antennae on anterior margin of prostomium, reaching chaetiger 4. Peristomium distinct, with two pairs of tentacular cirri; dorsal ones longer, reaching chaetiger 7; ventral ones reaching chaetiger 4. Dorsal cirri on chaetiger 1 longer, extending to chaetiger 9; those on chaetiger 2 shorter, reaching chaetiger 6. Remaining dorsal cirri longer or slightly shorter than body width, with less-developed cirrophores. Dorsal cirri on anterior parapodia longer than those on posterior ones, with small, spherical inclusions. Parapodia on anterior region subrectangular, posterior ones triangular. Falcigers on anterior parapodia numbering eight, bidentate; proximal tooth thicker and longer than distal one ( Figure 5C ); blades of superior falcigers 7.5 Mm long, those of inferior falcigers 10 Mm long. Posterior parapodia with six falcigers; blades 7.5–10 Mm long. Dorsal bayonet chaeta thin, curved, from chaetiger 8 ( Figure 5D ). Proventricle 0.15 mm long, 0.11 mm wide, through 2.5 segments, with 19 muscle cell rows. Pharynx between chaetigers 1 and 8, slightly coiled, with a trepan of 14 thin, sharp, similar teeth, except for slightly coarser lateral teeth ( Figure 5B ). Pygidium bilobed, with two short anal cirri.

Remarks

Autolytus mediterraneus comb. nov. is similar to A. quindecimdentatus Langerhans, 1884 and A. hesperidum, Claparède 1864 in terms of pharyngeal armature; all of them have a trepan with 12–14 triangular, small, equal teeth. However, A. mediterrraneus differs from A. quindecimdentatus in having relatively long antennae, long dorsal cirri in the middle region of the body (longer than body width), short proventricle (occupying 1.5 segments versus 2.5 segments in A. quindecimdentatus ). Autolytus hesperidium , which was originally described from the Gulf of Naples by Claparède (1868) and was erroneously proposed to be conspecific with A. prolifer (O. F. Müller, 1784) by Fauvel (1923), differs from A. mediterraneus in having median antenna as long as lateral ones (median antenna twice as long as lateral ones in A. mediterraneus ), dorsal cirri from chaetiger 2 to posterior end of similar size (dorsal cirri on A. mediterraneus are alternating long and short) and long proventricle occupying two segments. However, the pygidium of A. hesperidium , which has two small projections together with two long anal cirri, termed as ‘‘cirres spatulaires’’ (see Claparède 1868, Plate 14, Figure 1A ), appears to be similar to that of A. mediterraneus .

Distribution

Known only from the type locality; Secca Mediterranean ( Cognetti 1953b).

della Gajola, Gulf of Naples, western

Autolytus neapolitanus Cognetti, 1953

( Figure 6 )

Autolytus neapolitanus Cognetti 1953c, p 90 –92, Figure 1 ; Cognetti 1957, p 74, Figure 17.

Material examined

SZN-POL4, Lectotype, Station 9, Vico coralligeneous substrate, coll. Cognetti.

Equense, 10 October 1953, 25 m, on

Description

Specimen incomplete, anterior fragment, 1.75 mm long, 0.25 mm wide, H+ 1050.62 mm, for 27 chaetigers. Prostomium oval, with two pairs of reddish eyes in trapezoidal arrangement; anterior pair larger; one pair of ocular specks near anterior margin ( Figure 6A ). Palps short, hardly visible dorsally. Median antenna originating between posterior eyes, very long, extending to chaetiger 23; lateral ones next to ocular specks, reaching chaetiger 11. Nuchal epaulettes indistinct, reaching anterior region of chaetiger 1. Peristomium distinct, with two pairs of tentacular cirri; dorsal ones long, extending to chaetiger 11; ventral ones reaching chaetiger 5. Dorsal cirri on chaetiger 1 very long, extending to chaetiger 17; those on chaetiger 2 longer than body width; remaining ones either equal to or shorter than body width. Cirrophores less developed. Large granules present on dorsum of body and within parapodia, but those within cirri and antennae very small, inconspicuous. Parapodia conical in shape, larger in anterior region. Falcigers numbering 10 on anterior parapodia, with shafts coarsely serrated at tip; blades bidentate, proximal tooth larger and longer than distal one ( Figure 6C ); superior falcigers with blades 7.5 Mm long; inferior ones with blades 10 Mm long. Falcigers on middle parapodia numbering eight, morphologically similar to those on anterior parapodia but with shorter blades (5–7.5 Mm long). Dorsal simple chaeta bayonet-shaped, from chaetiger 7, thin, slightly curved ( Figure 6D ). Acicula numbering one per parapodium. Proventricle 0.28 mm long, 0.16 mm wide, through four segments, with 30 muscle cell rows. Pharynx between chaetigers 1 and 10, with one sinuation; trepan with 14 triangular, coarse, equal teeth ( Figure 6B ).

Remarks

Although morphological features of the specimen of Autolytus neapolitanus we examined coincide with its original description, some differences were encountered; the number of teeth on the trepan of the specimen examined are 14, whereas Cognetti (1953c) reported it as 20. However, the morphology of the teeth (long, coarse and triangular) seems to be identical to the description. He also mentioned five red spots at the bases of pharyngeal papillae, but, probably due to preservation, the specimen we examined does not have such spots. However, the location of proventricle and pharynx as well as their relative length are similar to those reported by Cognetti (1953c). The other similarity between the material we examined and the Cognetti’s description is the shape and length of antennae and cirri. Autolytus neapolitanus resembles A. quindecimdentatus Langerhans, 1884 in terms of the shape and the number of teeth of the trepan (see Gidholm 1966, Figure 7f ); however, teeth of the former species are larger than those of the latter. In addition, A. neapolitanus has longer antennae and dorsal cirri than those of A. quindecimdentatus .

Distribution

Known only from the type locality: Vico Equense, Gulf of Naples, Mediterranean Sea ( Cognetti 1953c, 1957).

Figures

Figure 1. Map of the investigated area with location of sampling sites.

Figure 2. (A) Anterior and posterior parts of Autolytus antondohrni with a stolon; (B) trepan; (C) inferior falciger on anterior parapodium; (D) dorsal simple chaeta. Scale bar: 100 Mm (A); 11 Mm (B); 5 Mm (C, D).

Figure 3. (A) Anterior and posterior parts of Autolytus cognettii; (B) trepan; (C) falcigers on anterior parapodium; (D) dorsal simple chaeta. Scale bar: 100 Mm (A); 17 Mm (B); 4.3 Mm (C, D).

Figure 4. (A) Ventral view of anterior and posterior parts of Autolytus convolutus; (B) trepan; (C) superior falciger on anterior parapodium; (D) dorsal simple chaeta. Scale bar: 100 Mm (A); 15 Mm (B); 5 Mm (C, D).

Figure 5. (A) Anterior and posterior parts of Autolytus mediterraneus; (B) trepan; (C) inferior falciger on anterior parapodium; (D) dorsal simple chaeta. Scale bar: 100 Mm (A); 14.5 Mm (B); 6.4 Mm (C, D).

Figure 6. (A) Anterior part of Autolytus neapolitanus; (B) trepan; (C) inferior falciger on anterior parapodium; (D) dorsal simple chaeta. Scale bar: 100 Mm (A); 28 Mm (B), 6 Mm (C, D).

Figure 7. (A) Anterior and posterior parts of Autolytus rubropunctatus; (B) trepan; (C) falcigers on anterior parapodium; (D) dorsal simple chaeta; (E) aciculae on middle parapodium. Scale bar: 100 Mm (A); 21 Mm (B); 5 Mm (C–E).