Pyrunculus pyriformis (A. Adams, 1850)

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 744-747

Pyrunculus pyriformis (A. Adams in Sowerby, 1850)

Figs 79A-D, 80

Bulla pyriformis A. Adams in Sowerby, 1850 [in 1848-50]: 589, pl. 125, fig. 128.

Synonyms:

Bulla nitida A. Adams in Sowerby, 1850 [in 1848-50]: 589, pl. 125, fig. 127.

Retusa semen Thiele, 1925: 271 .

Pyrunculus obesus Habe, 1950 a: 13, pl. 2, fig. 12.

TYPE MATERIAL. — B. pyriformis : 1 syntype BMNH 196940 . — B. nitida : not examined. — R. semen : 15 syntypes MNHB . — P. obesus : not examined.

TYPE LOCALITY. — B. pyriformis : China Seas. — B. nitida: Shores of Borneo. — R. semen: Siberut Island, Nias south Channel, Indonesia, 0°15.5’N, 98°4’E, 470 m, and Zanzibar Channel, Indian Ocean, 5°27.9’S, 39°18.8’E, 463 m [ Valdivia : stns 191, 199, and 245]. — P. obesus: Tosa Bay, 100- 200 m.

MATERIAL EXAMINED. — Philippines. MUSORSTOM 2: stn DR 350 m, 17 dd . — BIOCAL: stn DW 46 , 22°53’S, 167°17’E, 570-610 34, 13°28’N, 121°12’E, 155-167 m, 13 dd; stn CP 41, 13°16’N, m, 30 dd; stn DW 77 , 22°15’S, 167°15’E, 440 m, 20 dd . — BIOGEO- 122°46’E, 166-172 m,1 dd.— MUSORSTOM 3: stn CP 87, 14°00’N, CAL: stn KG 201, 22°40’S, 166°33’E, 595 m, 1 dd; stn KG 219, 120°19’E, 191-197 m, 1 dd; stn CP 96, 14°00’N, 120°18’E, 190- 22°39’S, 166°34’E, 570 m, depth, 7 dd. — LAGON: stn 830, Poin- 194 m, 1 dd; stn CP 98, 14°00’N, 120°18’E, 194-205 m, 1 dd; stn dimié Sector , 20°49’S, 165°19’E, 105-110 m, 7 dd . — BATHUS 1 : CP 99, 14°01’N, 120°19’E, 196-204 m, 1 dd; stn CP 100, 14°00’N, stn DE 654, 21°17’S, 165°57’E, Passe de Canala, 237-298 m, 28 dd; 120°18’E, 189-199 m, 2 dd; stn CP 101, 14°00’N, 120°19’E, 194- stn DW 655 , 21°17’S, 165°57’E, 375 m, 2 dd: stn DW 674 , Grande 196 m, 2 dd; stn DR 102, 14°01’N, 120°18’E, 192 m, 5 dd; stn DR Passe de Touho, 20°49’S, 165°19’E, 105-110 m, 4 dd; stn DW 677 , 140 , 11°43’N, 122°34’E, 93-99 m,>100 dd; stn CP 143, 11°29’N, 20°49’S, 165°19’E, 96-109 m, 1 dd; stn DW 683 , Passe de Hien- 124°11’E, 205-214 m, 2 dd. ghu, 20°35’S, 165°07’E, 380-400 m, 5 dd; stn DW 687 , 20°35’S, Indonesia. KARUBAR:stn DW 13 , Kai Islands, 05°26’S, 132°38’E, 165°07’E, 408-440 m, 24 dd; stn DW 688 , 20°33’S, 165°00’E, 270- 417- 425 m, 1 dd; stn DW 28 , 05°31’S, 132°54’E, 448-467 m, 4 dd; 282 m, 9 dd; stn DW 694 , Passe de Hienghène , 20°36’S, 164°58’E, stn DW 29 , 05°36’S, 132°56’E, 181-184 m, 9 dd (Fig. 79C); stn CP 400-500 m, 1 dd; stn CP 695, 20°35’S, 164°58’E, 410-430 m, 1 79, Tanimbar Islands, 09°16’S, 131°22’E, 239-250 m, 1 dd. dd; stn DE 696, 20°34’S, 164°57’E, 497-520 m, 11 dd; stn DE Coral Sea. MUSORSTOM 5: stn 357, Chesterfield Islands, 19°37’S, 697, 20°34’S, 164°58’E, 570-650 m, 6 dd; stn CP 698, 20°34’S, 158°46’E, 630 m, 1 dd. 164°57’E, 491-533 m, 8 dd; stn DE 700, Passe de Cap Baye , North of New Caledonia. MUSORSTOM 4: stn DW 149 , 19°08’S, 20°57’S, 165°35’E, 160-222 m,>100 dd; stn CP 701, 20°58’S, 163°23’E, 155 m, 6 dd; stn DW 150 , 19°07’S, 163°22’E, 110 m, 165°36’E, 302-335 m, 1 dd; stn DE 705, 21°02’S, 165°38’E, 350- 22 dd, 2 lv, 1 of them destroyed to dissect the gizzard plates (Fig. 400 m, 37 dd; stn DW 706 , Passe S.E. de Ngoe, 21°42’S, 166°34’E, 79D); stn DW 151 , 19°07’S, 163°22’E, 200 m, 3 dd; stn DW 156, 247-252 m, 51 dd; stn DW 713 , 21°45’S, 166°37’E, 250 m, 2 dd. 18°54’S, 163°19’E, 525 m, 2 dd; stn DW 161 , 18°39’S, 163°11’E, — HALIPRO 1: stn CP 866, 21°26’S, 166°17’E, 550-600 m, 1 dd. 550 m, 3 dd . — BATHUS 4 : stn DW 914 , Grand Passage, 18°49’S, — BATHUS 2 : stn DW 717 , Ile des Pins, 22°44’S, 167°17’E, 350- 163°15’E, 600-616 m, 24 dd; stn DW919 , 18°50’S, 163°17’E, 610- 393 m, 3 dd; stn DW 724 , 22°48’S, 167°26’E, 344-358 m, 2 dd; 660 m, 1 dd; stn CP 948, Passe de Hienghène , 20°33’S, 164°57’E, stn CP 738, Passe de Kouaré , 23°02’S, 166°57’E, 558-647 m, 2 533-610 m, 1 dd. dd; stn DW 754 , Passe de Dumbéa , 22°23’S, 166°13’E, 577-780 New Caledonia proper. VAUBAN: stn 40, 22°30’S, 166°24’E, 250- m, 1 dd; stn CP 760, 22°19’S, 166°11’E, 455 m, 1 dd; stn CP 761, 22°19’S, 166°11’E, 490-500 m, 10 dd . — BATHUS 4 : stn DW 882 , 149- 168 m, 10 dd; stn CP 1369, 18°11’S, 178°23’E, 392-433 m, Passe de St Vincent, 22°02’S, 165°56’E, 250-350 m, 4 dd; stn DW 10 dd; stn DW 1377 , 18°18’S, 178°02’E, 233-248 m, 4 dd; stn DW 885 , 22°05’S, 165°58’E, 250-300 m, 1 dd; stn DW 886 , Passe de 1384, 18°19’S, 178°06’E, 260-305 m; 3 dd . — SUVA 2: stn BS 10, Duroc, 21°01’S, 164°28’E, 250-300 m, 1 dd; stn DW 887 , 21°07’S, Viti Levu South Lagoon , 18°12’S, 178°30’E, 123 m, 1 dd . — BOR- 164°28’E, 320-344 m, 11 dd. DAU 1: stn CP 1402, 16°38’S, 179°36’E, 260-279 m, 1 dd; stn CP Norfolk Ridge. BATHUS 3 : stn DW 824 , Banc Jumeau Ouest, 1406, 16°39’S, 179°37’E, 360-380 m, 1 dd; stn CP 1407, 16°40’S, 23°19’S, 168°00’E, 601-608 m, 1 dd. 179°39’E, 499-527 m, 1 dd; stn DW 1408 , 16°02’S, 179°30’W, Loyalty Islands. Lifou. LIFOU 2000 : stn DW 1649 , Point Lefèvre 550-561 m, 1 dd, stn DW 1435 , 17°11’S, 178°45’W, 170-183 m, [= Nem], Baie du Santal , 20°54.2’S, 167°01.1’E, 150-200 m, 6 dd. 9 dd; stn DW 1464 , 18°09’S, 178°38’W, 285-300 m, 11 dd; stn Loyalty Ridge. BIOCAL: stn KG 06, 20°35’S, 166°53’E, 735 m, DW 1465 , 18°09’S, 178°39’W, 290-300 m, 1 dd; stn DW 1498 , 13 dd; stn DW 08 , 20°34’S, 166°54’E, 435 m, 1 dd; stn DW 51 , 18°41’S, 178°28’W, 300-307 m, 2 dd; stn CP 1506, 18°09’S, 23°05’S, 167°45’E, 680-700 m, 9 dd . — MUSORSTOM 6: stn DW 178°37’W, 294-300 m, 5 dd; stn CP 1507, 18°09’S, 178°38’W, 468, 21°06’S, 167°33’E, 600 m, 7 dd . — BIOGEOCAL: stn KG 227, 294-300 m, 2 dd.

21°33’S, 166°24’E, 500 m, 4 dd. Wallis and Futuna. MUSORSTOM 7: stn DW 505, Futuna Is- New Hebrides Arc. VOLSMAR:stn DW 51, Mont Gemini, 20°59’S, land, 14°19’S, 178°04’W, 245-400 m, 1 dd; stn DW 507, 14°20’S, 170°03’E, 450 m, 1 dd. 178°07’W, 419-425 m, 1 dd; stn DW 523, Wallis Island, 13°12’S, Vanuatu. MUSORSTOM 8: stn DW 972, 19°22’S, 169°28’E, 487- 176°16’W, 455-515 m, 4 dd; stn DW 601, 13°19’S, 176°17’W, 350 507 m, 1 dd; stn DW 976, 19°25’S, 169°27’E, 160-182 m, 1 dd; m, 7 dd; stn DW 608, 13°22’S, 176°08’W, 440-458 m; 1 dd; stn stn DW 1105, 15°03’S, 167°07’E, 154-179 m, 2 dd; stn DW 1045, DW 625, Banc Bayonnaise, 11°52’S, 179°34’W, 425-430 m, 1 dd. 16°54’S, 168°20’E, 459-488 m, 2 dd; stn DW 1094, 15°08’S, Tonga. BORDAU 2: stn DW 1509, Tongatapu, 21°05’S, 175°22’W, 167°12’E, 312-314 m, 1 dd; stn DW 1115, 15°10’S, 166°53’E, 456-510 m, 6 dd; stn DW 1538, 21°39’S, 175°19’W, 471-508 m, 5 147-150 m, 6 dd. dd; stn DW 1543, SW of Tongatapu, 21°16’S, 175°18’W, 427-436 Fiji. MUSORSTOM 10: stn CP 1319, Bligh Water, 17°16’S, m, 1 dd; stn DW 1549, S of Nomuka Islands, 20°38’S, 175°00’W, 178°02’E, 341-347 m, 3 dd; stn CP 1325, 17°16’S, 177°50’E, 500 m, 7 dd; stn DW 1552, 20°38’S, 174°58’W, 491-500 m, 8 282-322 m, 9 dd; stn DW 1329, 17°19’S, 177°47’E, 102-106 dd; stn DW 1553, 20°42’S, 174°54’W, 650-676 m, 3 dd; stn DW m, 3 dd; stn CP 1354, 17°43’S, 178°55’E, 959-963 m, 1 dd; stn 1567, NW of Tongatapu, 21 °02’S, 175°19’W, 351-356 m, 2 dd; DW 1359, 17°50’S, 178°48’E, 183-188 m, 10 dd; stn DW 1360, stn DW 1569, 21°02’S, 175°19’W, 433 m, 1 dd; stn DW 1585, 18°00’S, 178°48’E, 402-444 m, 1 dd; stn CP 1363, South of Viti Vava‘u Islands, 18°33’S, 173°57’W, 578 m, 3 dd (Figs 79A, B); Levu, 18°12’S, 178°33’E, 144-150 m, 9 dd; stn DW 1365, 18°13’S, stn DW 1589, 18°39’S, 173°54’W, 281 m, 2 dd, stn DW 1615, 178°32’E, 295-302 m, 32 dd; stn CP 1366, 18°12’S, 178°33’E, Seamount 23°03’S, 175°53’W, 482-504 m, 3 dd.

DISTRIBUTION. — Widespread in the Indo-Pacific. Material herein collected from the Coral Sea, Fiji, Indonesia, New Caledonia, Philippines, Tonga, Vanuatu and Wallis and Futuna (Fig. 80), in 90-959 m, live in 110 m.

DESCRIPTION. — Shell morphology. Length 5 mm, width 4 mm (largest specimen examined). Shell fragile, pyriform, with the widest region near the anterior end (Figs 79A, C). The outline of the shell varies among specimens; some are more elongate (Fig. 79A), others are wider and shorter (Fig. 79C). Shell with only 1 whorl visible, forming the entire shell, except for a visible portion of the top of the spire, which is encircled by the outer edge of the apical umbilicus. Apex rounded, depressed, umbilicate (Fig. 79B), with the aperture lip rising from the left side. The aperture lip forms a rounded wing connected to the columellar margin. Anterior end of the shell rounded. Umbilicus narrow in some specimens and absent in others. Aperture long, wide anteriorly, narrowing abruptly at about 1/3 of its length. Columellar margin thickened, with a small fold. Sculpture of a number of irregular spiral grooves, more conspicuous near the anterior and posterior ends and crossed by faint growth lines. The spiral grooves are absent in some specimens. Colour uniformly whitish.

Anatomy. The digestive system contains 3 triangular, unequal gizzard plates, one larger and the other two smaller, with 2 tubercles each (Fig. 79D). There is no radula.

REMARKS. — Pyrunculus pyriformis is a very variable species in shell morphology. Several species and subspecies names have been introduced for the different shell types. Shorter specimens with a wide anterior end of the shell have been included in the species P. pyriformis , with two subspecies: P. pyriformis pyriformis that includes animals with

FIG. 79. Shell morphology and anatomy of species of Pyrunculus Pilsbry, 1895 . A, Pyrunculus pyriformis (A. Adams in Sowerby, 1850), (5 mm), ventral view, Tonga, BORDAU 2 stn DW 1585; B, same shell, posterior view; C, (4.5 mm), ventral view, Indonesia, KARUBAR stn DW 29; D, gizzard plates, New Caledonia, MUSORSTOM 4 stn DW 150, scale bar = 200 Μm. E, Pyrunculus sp. , (4 mm), ventral view, Philippines, MUSORSTOM 3 stn CP 106; F, same shell, posterior view; G, gizzard plates, Indonesia, KARUBAR stn CP 71, scale bar = 200 Μm.

spiral lines, and P. pyriformis obesa (Habe, 1950) for animals with only growth lines (see Habe 1950a). Pyrunculus pyriformis obesa was originally introduced as a different species, but it has more recently been regarded as a subspecies of P. pyriformis (see Hori 2000c). More slender specimens, narrower at the base, have been included in the species Pyrunculus nitida , still maintained as a distinct species by Hori (2000c). The material here examined includes shells with morphologies similar to those of P. pyriformis pyriformis , P. pyriformis obesa and P. nitida , as well as intermediate forms between all of them. However, there is no correlation between the collection locality and the shape of the shell. Also, anatomical examination of specimens with different shell morphologies has shown no consistent differences. For these reasons, all the species and subspecies mentioned above are here regarded as synonyms.

Retusa semen , originally described from several Indo-Pacific localities (Thiele 1925), also falls within the morphological variation of P. pyriformis and is also considered a synonym.