Achelia sawayai Marcus 1940
Creators: name: Müller, Hans-Georg
name: Krapp, Franz
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Pycnogonida
Pantopoda
Ammotheidae
Achelia
Achelia sawayai

description: Achelia sawayai Marcus, 1940   
Figs. 4–5  
 Achelia sawayai Marcus, 1940: 81.   
 Achelia sawayai: Krapp & Kraeuter 1976: 342 (literature). Child 1979: 1–86. Stock 1979: 9. Child 1982: 356. Stock 1986: 400, 415. Müller 1989: 123. Stock 1989: 87. Müller 1990: 186. Müller 1990 x: 105. Müller 1990 y: 277. Stock 1990: 205. Müller 1992:43   
 Material: 3.— 6 males (1 ov.), 2 fem. (gravid), 1 juv. (SMF 1540), under large stone blocks on a sandy bottom, ca. 0.5m, 30.XII.1985.   
 6.— 5 males (2 ov.), 13 fem. (8 gravid), 4 juv. (SMF 1541), Thalassia, 2 m, 1.VIII.1985. 5 males (2 ov.), 2 fem. (2 gravid) (SMF 1542), same locality, 10.IX.1985. 5 males (1ov.), 8 females (SMF 1543), same locality, 3 m, 9.X.1985. 2 males (1 ov.), 1 juv. (SMF 1544), same locality, 12.XII.1985.   
 7.— 4 males (1 ov.) (SMF 1545), from Syringodium, 3 m, 12.XII.1985.   
 8.— 1 male (SMF 1546), jetty piles exposed to light, encrusted by corallinaceous red algae and hydroids, 0-1 m, 24.IV.1985. 1 male, 2 fem. (SMF 1547), jetty piles exposed to light, encrusted by algae and poriferans, 10.V.1985. 1 male (SMF 1548), from poriferans and hydroids on shaded jetty piles, 0–1 m, 14.V.1985. 4 males (3 ov.), 4 fem. (SMF 1549), piles of jetty exposed to light with poriferans and hydroids, 0–1 m, 14.V.1985. 3 males (1ov.) (SMF 1550), shaded jetty piles with poriferans and hydroids, 0–1 m, 19.V.1985. 1 fem. (gravid) (SMF 1551), shaded jetty piles with poriferans and hydroids, 1–3 m, 17.VI.1985. 1 male (SMF 1552), piles of jetty exposed to light with detritus and Cnidoscyphus, 0–1m, 31.VII.1985. 4 males (3 ov.), 9 fem. (6 gravid) (SMF 1553), shaded jetty piles with Cnidoscyphus, 0–1 m, 17.X.1985. 1 male, 2 fem. (1 gravid) (SMF 1554), same locality, 24.XI.1985. 1 male, 1 fem. (gravid) (SMF 1555), same locality, with different encrusting organisms, 0–1 m, 17.XII.1985. 1 male (ov.) (SMF 1556), same locality, with hydroids, 0–2 m, 1.II.1986. 2males, 1 fem. (gravid) (SMF 1557), same locality, with poriferans and hydroids, 0–1 m, 14.III.1986.   
 9.— 1 juv. (SMF 1558), under large stone blocks on a sandy bottom, 0–0.5 m, 31.XII.1985.   
 10.— 5 males (1ov.), 6 fem. (3 gravid), 16 juv. (SMF 1559), algae on rock, lower mesolittoral, 7.V.1985. 2 juv. (SMF 1560), same locality, 8.V.1985. 1 male (ov.), 3 fem. (2 gravid), 8 juv. (SMF 1561), 10.V.1985. 1 male, 1 fem. (gravid), 6 juv. (SMF 1562), phaeophyceans on rock, lower mesolittoral, 12.V.1985. 2 males (ov.), 3 fem. (2 gravid), 4 juv. (SMF 1563), Sargassum growing on rock, mesolittoral, 3.VII.1985. 5 juv. (SMF 1564), with Digenia and Sargassum on rock, mesolittoral, 31.IX.1985.   
 15.— 2 fem. (gravid) (SMF 1565), from phaeophyceans, 5–7 m, 22.V.1985.   
 16.— 55 males (3ov.), 67 fem. (39 gravid), 23 juv. (SMF 1566), phaeophyceans on rock, mesolittoral, 22.V.1985. 8 males (1 ov.), 5 fem. (4 gravid), 1 juv. (INVEMAR), phaeo- and rhodophyceans on rock, mesolittoral, 15.VII.1985. 1 male (ZSM), phaeophyceans on rock, lower mesolittoral, 12.II.1986.   
 17.— 3 males, 8 fem. (6 gravid) (ZMA 3354), from Cnidoscyphus on rock, mesolittoral, 8.VII.1985. 2 fem. (gravid) (SMF 1567), same locality, 15.VII.1985. 1 fem., 3 juv. (SMF 1568), under blocks of rock, 0–0.5 m, 7.I.1986.   
 18.— 1 fem. (SMF 1569), from Halocordyle on rock, ca. 1 m, 23.VI.1985.   
 19.— 1 male, 2 fem. (gravid) (ZSM), Thalassia, 5 l of substratum, 0.5–4 m, 27.VI.1985. 1 male (SMF 1570), same locality, 8.VIII.1985. 2 males (SMF 1571), same locality, 7.XII.1985. 3 males (1 ov.), 4 fem. (2 gravid) (ZFMK), same locality, 12.II.1986. 1 fem. (gravid) (SMF 1572), same locality, 3.III.1986. 8 males (3 ov.), 3 fem. (gravid), 2 juv. (SMF 1573), same locality, 2.V.1986.   
 20.— 17 males (3 ov.), 15 fem. (14 gravid), 3 juv. (SMF 1574), Sargassum cymosum on rock, 5l of substratum, 0–0.5 m, 7.VI.1985. 2 males, 3 fem. (gravid) (USNM), same locality, 9.IX.1985. 2 males, 2 fem. (gravid) (SMF 1575), same locality, 2.X.1985. 1 fem. (gravid) (SMF 1576), same locality, 8.XI.1985. 2 males (1 gravid) (SMF 1577), same locality, 7.XII.1985. 3 males, 2 fem. (gravid) (SMF 1578), same locality, 7.I.1986. 3 males (SMF 1579), same locality, 3.III.1986. 1 male (ov.) (SMF 1580), same locality, 3.IV. 1986. 1 male (SMF 1581), same locality, 2.V.1986.   
 21.— 17 males (7 ov.), 14 fem. (11 gravid), 3 juv. (SMF 1582), Digenia simplex on rock, 5 l of substratum, mesolittoral, 7.VI.1985. 1 juv. (SMF 1583), same locality, 5.VII.1985. 11 males (2 ov.), 8 fem. (2 gravid), 1 juv. (SMF 1584), same locality, 8.VII.1985. 11 males (3 ov.), 7 fem. (gravid), 8 juv. (SMF 1585), same locality, 13.VIII.1985. 1 male, 2 fem. (gravid), 5 juv. (SMF 1586), same locality, 9.IX.1985. 1 male, 1 fem. (gravid) (SMF 1587), same locality, 2.X.1985. 8 males (3 ov.), 9 fem. (gravid), 15 juv. (SMF 1588), same locality, 8.XI.1985. 1 male, 4 fem. (2 gravid), 13 juv. (SMF 1589), same locality, 12.II.1986. 2 juv. (SMF 1590), same locality, 3.IV.1986. 2 juv. (SMF 1591), same locality, 2.V.1986.   
 22.— 19 males (8 ov.), 11 fem. (5 gravid), 15 juv. (SMF 1592), reef surface from Halimeda, mesolitoral, 14.IV.1986.   
 23.— 1 male (SMF 1593), drifting Sargassum over sandy bottom, 7–9 m, 31.V.1985.   
 24.— 1 male (SMF 1594), Thalassia with corallinaceans, 2 m, 4.IX.1985. 1 fem. (gravid) (SMF 1595), Thalassia, 1 m, 4.IX.1985. 1 male (SMF 1596), same locality, 0.5–1 m, 8.IX.1985. 7 males (2 ov.), 4 fem. (gravid), 1 juv. (SMF 1597), Thalassia with corallinaceans, 1 m, 21.I.1986.   
 27.— 2 males (1 ov.), 1 fem. (gravid), 2 juv. (SMF 1598), coral rubble in a stand of Thalassia, 0.5 m, 13.IX.1985.   
 28.— 1 male, 3 fem. (gravid), 4 juv. (SMF 1559), under stones in about 0.5 m, 4.IV.1986.   
 31.— 1 fem. (gravid), 1 juv. (SMF 1600), from phaeophyceans and rhodophyceans on rock, mesolittoral, 9.IV. 1986.   
 33.— 1 fem. (gravid) (SMF 1601), Thalassia, 0.5 m, 17.I.1986.   
 34.— 2 males (ov.), 5 fem. (1gravid), 3 juv. (SMF 1602), under stones in about. 0.5 m, 10.IV.1986.   
 38.— 12 males (4 ov.), 6 fem. (3 gravid), 8 juv. (SMF 1603), Thalassia, 0.5 m, 17.III.1986.   
 39.— 9 males (4 ov.), 7 fem. (gravid), 4 juv. (SMF 1604), from stones, 0–0.5 m, 17.III.1986. 11 males (6 ov.), 4 fem. (gravid), 4 juv. (SMF 1605), same locality, 14.IV.1986.   
 45.— 3 males, 1 fem. (SMF 1606), from algae, hydroids and bryozoans on rock, 6–10 m, 26.IX.1985.   
 Description of male: Trunk outline almost circular, all segments fused; crurigers touching or slightly separated. Cephalon bearing low tubercle above origin of palps, terminating in one short seta.   
 Ocular process about as high as its basal diameter, distally rounded, eyes distinctly pigmented. Crurigers 1–4 often with low setaceous tubercle close to dorso-distal margin. Abdomen feebly bent dorsally, distally narrower and adorned with some setae; abdomen overreaching 4 th crurigers by more than half of its length. Proboscis very slender, broadest in basal half. Scape of cheliphores about 2.5 times as long as diameter, dorsodistally with some regularly spaced short setae. Cheliphores mere stumps, with short lateral seta. Palps with 8 articles; 2 nd and 4 th articles longest, about three times as long as broad; articles 6–8 with several ventral or distal setae. Oviger of 10 articles; 4 th and 5 th the longest, slender; articles 8–10 with pairs of serrated flattened setae. Legs relatively robust; coxae 1 of all legs with robust dorsal tubercle and additional tubercle on their antero-lateral and postero-lateral aspects, which may be somewhat variable; coxa 2 of all legs distally adorned with small antero- and postero-lateral tubercles bearing some setae; coxa 3 of all legs without tubercles; cement gland opening via dorso-distal cone-shaped process of the femur, ending in very short tube-shaped duct; tibia 1 and tibia 2 of about same length, with several long setae and some slender dorsal spiniform setae; tarsus slightly longer than broad, with 3 short ventral setae; propodus feebly curved, without heel; sole with 6–8 short stiff setae; main claw relatively short and robust, about 1/3 as long as propodus; auxiliary claws about 4/5 as long as main claw.   
 Measurements: Length 0.41; width 0.43 (across 2 nd crurigers); length of abdomen 0.14; length of proboscis 0.44; length of cheliphores 0.11; leg 3: coxa1, 0.11; coxa 2, 0.11; coxa 3, 0.10; femur 0.31; tibia 1, 0.26; tibia 2, 0.31; tarsus 0.04; propodus 0.24; main claw 0.08; auxiliary claw 0.07.   
 Female: generally similar to males, with the following differences: coxae 1 of all legs distally with 2 small tubercles only which bear setae; dorso-distal tubercles on coxae 2 of all legs less developed. Ovigers shorter, 7 th article shorter than in males; specialized spines on articles 5–10.   
 Remarks: The development of tubercles on trunk segments and on coxae 1–2 of all legs is very variable in both sexes, as in many species of this difficult genus, which badly needs a revision.   
 Achelia sawayai colonizes a variety of substrata and seems to be restricted to shallow water (in our research area 0–10 m). Most specimens came from stands of algae and seagrass in the upper sublittoral from 0– 2 m. Ovigerous males were sampled all year round, eurychronous.   
 Distribution: Since the original description from Brazil the species has been collected in great numbers; it may be regarded as one of the most frequent species in the tropical western Atlantic. Some occasional findings outside that region were recorded from western Africa (Fage 1949a: 28), Madagascar (Stock 1974: 14), the isles of Fiji (Müller 1990b: 105) and the Society Archipelago (Moorea, Müller 1989: 124; Bora Bora, Müller 1990a: 186).
description: Published as part of Müller, Hans-Georg & Krapp, Franz, 2009, The pycnogonid fauna (Pycnogonida, Arthropoda) of the Tayrona National Park and adjoining areas on the Caribbean coast of Colombia 2319, pp. 1-138 in Zootaxa 2319 (1) on pages 17-21, DOI: 10.11646/zootaxa.2319.1.1, http://zenodo.org/record/5317868