This is possibly one of the smallest mygs in USA and probably the smallest myg found in CA! Mature females are less than 6mm in body length and probably under 1cm DLS! Eggsacs are 1.5-2mm wide lenticulars that contain 4-7 eggs!
Click to see full size image
YES: Riverside, San Diego, Orange
Species Hexurella sp
Specimen Code: MY00724; Determined By: J. Bond; Date Determined: 2004; Stage/ Sex: 00; Collected By: W.R. Icenogle; Date(s) Collected: 5 Mar 2000; Coll Record Date: Jul 21, 2003; Locality Code: ICE1; Locality Name: 2.5 miles East of San Juan Fire Station; District: Orange; State/ Prov: California; Country: United States of America; Loc Latitude: 33°35'27"N; Loc Longitude: 117°28'31"W
There may be people who like centipedes. I have seen people handling tarantulas and scorpions, but never a centipede handler. I would regard such a person with deep suspicion...Now what sort of man or woman or monster would stroke a centipede on its underbelly "And here is my big good centipede." If such a man exists, I say kill him without more ado. He is a traitor to the human race.
William S. Burroughs The Western Lands
Last edited by cacoseraph on Mon Jun 15, 2009 11:40 am; edited 3 times in total
Very little has been published on the biology of the mecicobothriids. They are mostly smallspiders that live close to the soil in crevices, under rocks, pieces of wood, or other ground objects, and are often found quite deep in
organic ground litter. Although they are active animals they spend most of their lives within the confines of a sheet web. From their retreat funnel they spin out a flat sheet a few inches wide and run upright over the surface. Older webs soon become a complex of tubes and
supporting sheets of white silk laid down in available spaces beside, above, or beneath the principal sheet. Typically, the webs are mostly
hidden from view by covering objects or detritus.
http://digitallibrary.amnh.org/dspace/bitstream/2246/5425/1/N2687.pdf
Quote:
In Arizona and southern California the minute species of Hexurella spin webs under objects on the ground or hide them deep in pine needles or under oak leaves. The capturing techniques of the mecicobothriids are likely to be the same as those of diplurids. The long, widely spaced, flexible spinnerets of both are ideal organs for laying down sheet webs.
http://digitallibrary.amnh.org/dspace/bitstream/2246/5425/1/N2687.pdf
Quote:
Most mygalomorph spiders are known to be perennial, living more than one year, and this is probably true for the mecicobothriids. Some
evidence of this is offered by the fact that immature specimens of various sizes can be found during most months of the year. Mature females, usually accompanied by nearby immature stages, occur during almost all months of the year but are most abundant in summer and fall.
http://digitallibrary.amnh.org/dspace/bitstream/2246/5425/1/N2687.pdf
_________________
Quote:
There may be people who like centipedes. I have seen people handling tarantulas and scorpions, but never a centipede handler. I would regard such a person with deep suspicion...Now what sort of man or woman or monster would stroke a centipede on its underbelly "And here is my big good centipede." If such a man exists, I say kill him without more ado. He is a traitor to the human race.
William S. Burroughs The Western Lands
Last edited by cacoseraph on Tue Apr 15, 2008 11:31 am; edited 4 times in total
There may be people who like centipedes. I have seen people handling tarantulas and scorpions, but never a centipede handler. I would regard such a person with deep suspicion...Now what sort of man or woman or monster would stroke a centipede on its underbelly "And here is my big good centipede." If such a man exists, I say kill him without more ado. He is a traitor to the human race.
William S. Burroughs The Western Lands
Last edited by cacoseraph on Tue Apr 15, 2008 11:14 am; edited 1 time in total
The small size of the species of Hexurella makes them of special interest but questions of their longevity and biology remain for future investigation. All presently known specimens were collected from March to May at one of seven well separated stations. Mature males and females and immatures were found together at these times.
[...]
Egg sacs were produced, also in the laboratory, by four females of Hexurella rupicola from Johnson Canyon, California, on May 6, 25, and 26, and June 2. These varied in size from 1.7 to 2.2 mm. in diameter
and contained four, six, seven, and seven eggs, respectively. This small count is in keeping with the small size of the females, inasmuch as their abdomens cannot accommodate additional eggs, and is again about average for spiders of this size. This information was supplied by Mr.
Wendell Icenogle, who is continuing his study of these spiders to discover whether multiple egg sacs are ever produced by females.
http://digitallibrary.amnh.org/dspace/bitstream/2246/5425/1/N2687.pdf
_________________
Quote:
There may be people who like centipedes. I have seen people handling tarantulas and scorpions, but never a centipede handler. I would regard such a person with deep suspicion...Now what sort of man or woman or monster would stroke a centipede on its underbelly "And here is my big good centipede." If such a man exists, I say kill him without more ado. He is a traitor to the human race.
William S. Burroughs The Western Lands
Last edited by cacoseraph on Tue Apr 15, 2008 11:32 am; edited 5 times in total
KEY TO GENERA OF MECICOBOTHRIIDAE
1. Abdomen with separate anterior and dorsal tergal
plates (as in fig. 37); anterior lateral spinnerets
two-segmented (as in fig. 52) .............2
Abdomen with anterior and dorsal tergal plates
fused into single scutum; anterior lateral spinnerets
one-segmented (fig. 59) or absent (fig.
6; Oregon and Washington ....... .Hexura
2. Posterior lateral spinnerets three-segmented (as in
fig. 36) ......................... 3
Posterior lateral spinnerets four-segmented (fig.
71); Arizona, California, and Baja California
....Hexurella
3. Cephalothorax with pronounced pleurital extensions
at posterolateral corners (figs. 51, 53);
California .................... Megahexura
Cephalothorax without pronounced pleurital extensions
at posterolateral corners (fig. 35);
Argentina ................. Mecicobothrium
[pg 16-17 of pdf]
Quote:
HEXURELLA, NEW GENUS
Hexurella Gertsch, 1979, p. 120 (nomen nudum).
TYPES SPECIES: Hexurella pinea, new species.
ETYMOLOGY: The generic name is from Hexura and the Latin suffix ella (little), referring to the small size.
DIAGNOSIS: Specimens of Hexurella may be easily distinguished from other mecicobothriids by the four-segmented posterior lateral spinnerets
(fig. 71). The members of this genus are among the smallest of all mygalomorph spiders and in North America are rivalled only by the diplurids of the genus Microhexura. The two groups are much alike in superficial appearance but the presence of six spinnerets, tergal plates on the abdomen, and a palpal conductor readily differentiate Hexurella.
DEScRlPrION: Small spiders (length 2.5-5.0) similar in appearance and structure to Mecicobothrium but differing as follows: Posterior eye row straight or slightly procurved. Clypeus sloping, equal in width to long diameter of anterior lateral eye. Posterior three pairs of sigilla inconspicuous or not evident; anterior pair broad. Chelicerae without apophyses, short, projecting ventrad; retromargin with band of hairs and one or two teeth near tip of fang. First leg of males moderately incrassate, with or without patch of clasping spines on femur or tibia; terminal segments with few spines. Posterior lateral spinnerets four-segmented, last two segments with false sutures. Four epigynal receptacles subequal in length. Tibia of male palp incrassate; tarsus without prolateral lobe, with shallow retrolateral invagination; conductor and embolus coiled.
KEY TO SPECIES OF HEXURELLA
1. Carapace pale yellow or white, without contrasting
markings (fig. 72); posterior eye row
usually straight (fig. 74); leg I of males with
patch of clasping spines (figs. 76, 83); Arizona
.............................. 2
Carapace reddish brown, with contrasting markings
(fig. 73); posterior eye row usually
slightly procurved (fig. 75); leg I of males
without patch of clasping spines (figs. 86, 89);
California and Baja California ............3
2. Femur I of male with, tibia I without, patch of
spines on prolateral surface (fig. 76); bursa
copulatrix of females relatively narrow (fig.
80); pine forest near Prescott, Arizona......
..................................pinea
Femur I of male without, tibia I with, patch of
spines on prolateral surface (fig. 83); bursa
copulatrix of females relatively wide (fig. 81);
oak and ground litter on mountains of southeastern
Arizona ..................apachea
3. Conductor and embolus of male closely appressed
(fig. 87); female unknown; oak litter of northern
Baja California .................encina
Conductor and embolus of male well separated
(fig. 90); female with shallow bursa copulatrix
(fig. 82); under rocks in ground litter on
foothills of southern California .....rupicola
[pg29-30 of pdf]
Quote:
Hexurella rupicola, new species
Figures 82, 89-91
TYPE: Male holotype from 1 mi. south of Temecula, Riverside County, California (March 6, 1971; J. M. Rowland), deposited in AMNH.
ETYMOLOGY: The specific name is from the Latin rupes (rock) and incola (inhabitant), referring to the habitat under rocks.
DIAGNOSIS: Hexurella rupicola resembles H. encina but may be distinguished by the widely separated embolus and conductor of the male
palp (fig. 90). Females of H. rupicola have a distinctively shallow bursa copulatrix (fig. 82).
FEMALE (Johnson Canyon): Total length, including chelicerae, 4.5. Coloration as in H. encina, structure as in H. pinea except as noted; lengths and widths of: carapace 1.50, 1.20; sternum 0.90, 0.75; labium 0.15, 0.30; endites 0.40, 0.35; abdomen 3.00, 1.50. Clypeus equal in width to slightly more than long diameter of anterior lateral eye. Ratio of eyes, anterior lateral: anterior median: posterior lateral: posterior median, 4:2:3:3. Anterior eye row procurved as seen from front, but line
along posterior edges nearly straight; median eyes separated by half their radius, as far from lateral eyes. Posterior eye row slightly procurved;
median eyes separated by nearly twice their diameter. Chelicerae 0.50 long, 0.33 wide; promargin with nine teeth and denticles, retromargin with one tooth and two denticles near tip of fang. Measurements: Epigynum similar to H. pinea but with shallower bursa copulatrix (fig. 82).
MALE (holotype): Total length, including chelicerae, 2.30. Coloration and structure as in H. encina except as noted; lengths and widths of: carapace 1.00, 0.74; sternum 0.60, 0.46; labium 0.07, 0.20; endites 0.23, 0.21; abdomen 1.30, 0.75. Ratio of eyes, anterior lateral: anterior median: posterior lateral: posterior median, 10:5:6:6. Posterior median eyes separated by nearly twice their diameter. Cheliceral retromargin
with one tooth near tip of fang. Depth of femur I less than half its length (fig. 89). Measurements:
[SEE PDF FOR MEASUREMENTS TABLE]
Palp (figs. 90, 91) with distinctly separated embolus
and conductor.
OTHER MATERIAL EXAMINED: California: Riverside Co.: near De Luz road, 2.5 mi. S Murrieta, Apr. 9-28, 1977-1978, under rocks below chaparral on canyon side, elevation 1200 ft. (W. Icenogle), c, Y Y. San Diego Co.: Johnson Canyon, N end of Harvest Road, 2 mi. SW Lower Otay Lake, Apr. 7-16, 1977-1978, under rocks on grassy canyon side, elevation 500 ft. (S. Johnson, W. Icenogle), dcT, YY.
DISTRIBUTION: Southern counties of California
(fig. 34).
[pg 33 of pdf]
http://digitallibrary.amnh.org/dspace/bitstream/2246/5425/1/N2687.pdf
_________________
Quote:
There may be people who like centipedes. I have seen people handling tarantulas and scorpions, but never a centipede handler. I would regard such a person with deep suspicion...Now what sort of man or woman or monster would stroke a centipede on its underbelly "And here is my big good centipede." If such a man exists, I say kill him without more ado. He is a traitor to the human race.
William S. Burroughs The Western Lands
Last edited by cacoseraph on Tue Apr 15, 2008 11:49 am; edited 7 times in total
Gertsch, W. J. & N. I. Platnick. 1979. A revision of the spider family Mecicobothriidae (Araneae, Mygalomorphae). Am. Mus. Novit. 2687: 1-32.
(see pdf above!!!!!!!!!!!)
Platnick, N. I. & R. R. Forster. 1982. On the Micromygalinae, a new subfamily of mygalomorph spiders (Araneae, Microstigmatidae). Am. Mus. Novit. 2734: 1-13. _________________
Quote:
There may be people who like centipedes. I have seen people handling tarantulas and scorpions, but never a centipede handler. I would regard such a person with deep suspicion...Now what sort of man or woman or monster would stroke a centipede on its underbelly "And here is my big good centipede." If such a man exists, I say kill him without more ado. He is a traitor to the human race.
William S. Burroughs The Western Lands
Last edited by cacoseraph on Mon Dec 07, 2009 6:05 pm; edited 14 times in total
There may be people who like centipedes. I have seen people handling tarantulas and scorpions, but never a centipede handler. I would regard such a person with deep suspicion...Now what sort of man or woman or monster would stroke a centipede on its underbelly "And here is my big good centipede." If such a man exists, I say kill him without more ado. He is a traitor to the human race.
There may be people who like centipedes. I have seen people handling tarantulas and scorpions, but never a centipede handler. I would regard such a person with deep suspicion...Now what sort of man or woman or monster would stroke a centipede on its underbelly "And here is my big good centipede." If such a man exists, I say kill him without more ado. He is a traitor to the human race.
There may be people who like centipedes. I have seen people handling tarantulas and scorpions, but never a centipede handler. I would regard such a person with deep suspicion...Now what sort of man or woman or monster would stroke a centipede on its underbelly "And here is my big good centipede." If such a man exists, I say kill him without more ado. He is a traitor to the human race.
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; Oregon and Washington ....... .Hexura
