4.5 Stylocheiron longicorne Sars, 1883
S. longicorne Sars, 1883: p. 32 - Sars, 1885: pp.
144, 145, pl. 27 fig. 5 - Hansen, 1908: p. 93 -
Hansen, 1910: pp. 120, 121, pl. 16 fig. Sa-h -
Hansen, 1912: pp. 279, 280, pl. 11 fig. 4a-b- Zimmer, 1914: pp. 436, 437- Hansen, 1916: p. 652Colosi, 1917: pp. 197, 198, pl. 15 figs. 39-42- Tattersall, 1924: p. 30- Tattersall, 1927: pp. 26, 27Illig, 1930: p. 527- Ruud, 1936: p. 15 et seq., figs.
5, 17 - Tattersall, 1939: pp. 222, 223 - Banner,
1950: pp. 37, 38, pl. 4 fig. 5 - Boden, 1954: pp.
234-236, fig. 21a-c- Boden et al., 1955: p. 388,
fig. 53a-c- Boden, 1955: p. 345- Lewis, 1955: p.
197, fig. 5- Nepgen, 1957: p. 11, pl. 12- Boden,
1961: p. 260 - Ro ger, 1968: p. 38, fig. 15, tab.1 -
Mauchline and Fischer, 1969: pp. 98, 100, fig. 35
- Mauchline, 1971a: p. 7, fig.14a - Mauchline,
1971b: p. 13, fig. 14 a-g- Ramirez, 1971: pp. 402404, pl. 1 fig. 4, pl. 4, fig. 3 - Brinton, 1975: pp.
215, 216, figs. 115, 124a-f- Antezana and Brinton, 1981:pp.689,694,figs.228-233.
S. mastigophorum Chun,1887: p. 30 (partim).
Body length -
female: 7.6 mm (1 specimen)
male: 7.2 mm (1 specimen)
Description
Frontal plate of carapace triangular and projected in very thin and short rostrum. Gastric area
bearing short and abrupt mid-dorsal keel. Eyes
large and constricted into two lobes that are
twice as high as wide. Upper lobe as wide or
somewhat wider than lower lobe and with numerous crystal, elongated cones. Antennular peduncle in males as long as carapace. Basal segment similar in both sexes, lacking lobes or similar processes. Distal segments differ between
-~
~-------~
- - - - - - - - -
sexes, being much longer and more slender in females than in males. 3rd endopodite greatly
elongated, ending in false chela with numerous
spines on propodus and dactylus. Abdominal
segments lacking spines or keels. 6th abdominal
segment longer than high; length and height varies considerably. Terminal process of petasma
somewhat broader at base, with distal half forming obtuse angle with proxima! half. Distal edge
bearing 6 tiny denticles. Proxima! process as
long and thick as terminal process and with
smooth edge. Spiniform process robust and
somewhat curved. Lateral process smaller and
less curved than proxima! and terminal processes. Thelycum consists entirely of the coxal plates
forming a pocket which is delimited ventrally by
a triangular opening. Two spermatophores are
attached to the lateral surface of the pocket bottom. 4 interna! and 5 externa! bristles are inserted on the front edge of the coxal plates ( Costanzo
and Guglielmo 1976a).
Remarks
The ratio of the width of the upper lobe/lower
lobe and that of the height/length of the 6th abdominal segment vary considerably within the
species. Brinton (1962a) used these characters,
along with the number of crystal cones, to identify long and short forms of S. longicorne. Specimens from colder waters off Chile resemble long
forms even though they have 7-8 crystal cones,
which corresponds to the number of cones in the
short form.
Distribution
S. longicorne is an equatorial, subtropical epipelagic species (Brinton 1962b ). It is found in the
Atlantic and Pacific Oceans, as well as in the
S. longicorne Sars, 1883: p. 32 - Sars, 1885: pp.
144, 145, pl. 27 fig. 5 - Hansen, 1908: p. 93 -
Hansen, 1910: pp. 120, 121, pl. 16 fig. Sa-h -
Hansen, 1912: pp. 279, 280, pl. 11 fig. 4a-b- Zimmer, 1914: pp. 436, 437- Hansen, 1916: p. 652Colosi, 1917: pp. 197, 198, pl. 15 figs. 39-42- Tattersall, 1924: p. 30- Tattersall, 1927: pp. 26, 27Illig, 1930: p. 527- Ruud, 1936: p. 15 et seq., figs.
5, 17 - Tattersall, 1939: pp. 222, 223 - Banner,
1950: pp. 37, 38, pl. 4 fig. 5 - Boden, 1954: pp.
234-236, fig. 21a-c- Boden et al., 1955: p. 388,
fig. 53a-c- Boden, 1955: p. 345- Lewis, 1955: p.
197, fig. 5- Nepgen, 1957: p. 11, pl. 12- Boden,
1961: p. 260 - Ro ger, 1968: p. 38, fig. 15, tab.1 -
Mauchline and Fischer, 1969: pp. 98, 100, fig. 35
- Mauchline, 1971a: p. 7, fig.14a - Mauchline,
1971b: p. 13, fig. 14 a-g- Ramirez, 1971: pp. 402404, pl. 1 fig. 4, pl. 4, fig. 3 - Brinton, 1975: pp.
215, 216, figs. 115, 124a-f- Antezana and Brinton, 1981:pp.689,694,figs.228-233.
S. mastigophorum Chun,1887: p. 30 (partim).
Body length -
female: 7.6 mm (1 specimen)
male: 7.2 mm (1 specimen)
Description
Frontal plate of carapace triangular and projected in very thin and short rostrum. Gastric area
bearing short and abrupt mid-dorsal keel. Eyes
large and constricted into two lobes that are
twice as high as wide. Upper lobe as wide or
somewhat wider than lower lobe and with numerous crystal, elongated cones. Antennular peduncle in males as long as carapace. Basal segment similar in both sexes, lacking lobes or similar processes. Distal segments differ between
-~
~-------~
- - - - - - - - -
sexes, being much longer and more slender in females than in males. 3rd endopodite greatly
elongated, ending in false chela with numerous
spines on propodus and dactylus. Abdominal
segments lacking spines or keels. 6th abdominal
segment longer than high; length and height varies considerably. Terminal process of petasma
somewhat broader at base, with distal half forming obtuse angle with proxima! half. Distal edge
bearing 6 tiny denticles. Proxima! process as
long and thick as terminal process and with
smooth edge. Spiniform process robust and
somewhat curved. Lateral process smaller and
less curved than proxima! and terminal processes. Thelycum consists entirely of the coxal plates
forming a pocket which is delimited ventrally by
a triangular opening. Two spermatophores are
attached to the lateral surface of the pocket bottom. 4 interna! and 5 externa! bristles are inserted on the front edge of the coxal plates ( Costanzo
and Guglielmo 1976a).
Remarks
The ratio of the width of the upper lobe/lower
lobe and that of the height/length of the 6th abdominal segment vary considerably within the
species. Brinton (1962a) used these characters,
along with the number of crystal cones, to identify long and short forms of S. longicorne. Specimens from colder waters off Chile resemble long
forms even though they have 7-8 crystal cones,
which corresponds to the number of cones in the
short form.
Distribution
S. longicorne is an equatorial, subtropical epipelagic species (Brinton 1962b ). It is found in the
Atlantic and Pacific Oceans, as well as in the