Hypochilus bernardino Catley 1994

Ciaccio, Erik, Debray, Andrew & Hedin, Marshal, 2022, Phylogenomics of paleoendemic lampshade spiders (Araneae, Hypochilidae, Hypochilus), with the description of a new species from montane California, ZooKeys 1086, pp. 163-204 : 163

Hypochilus bernardino Catley 1994

Figs 9 , 10 , 11 , 12 , 13

Hypochilus petrunkevitchi Gertsch 1958: Forster et al. 1987: 22 (San Bernardino county records).

Hypochilus bernardino Catley 1994: 10, figs 7, 11, 25, 33, 36-39.

Material examined.

F from Forsee Creek (SDSU_G2893), Ms from East Fork Mountain Home Creek (SDSU_G2929-2932), see Suppl. material 2.

Diagnosis.

Following from the original diagnosis of Catley (1994), we paid closest attention to the length of the PTaL (should be shorter in H. bernardino ), and the PTW/PTL (should be shorter and more thickened proximally in H. bernardino ). We found that PTaL overlaps with northern populations (Table 5 ), and is therefore not diagnostic. The PTW/PTL ratio is generally smaller in H. bernardino , but there is some overlap with northern populations, again calling into question the diagnostic value of this character. We did find that the male CdL is consistently shorter in H. bernardino (Table 5 ), and hypothesize this as a new morphological character diagnostic for the species. Again, consistent with a hypothesis of phylogenetic niche conservatism imparting morphological stasis, the species is only weakly morphologically diagnoseable. The disjunct geographic distribution (Fig. 9 ) and hundreds of diagnostic nucleotide changes (alignments at https://doi.org/10.5061/dryad.g1jwstqsd) can also be used to recognize this species.

Genetic data.

SRA Accession numbers: SAMN21239435-SAMN21239437.

New records.

California, San Bernardino County, San Bernardino Mountains, Camp Creek east of Forest Falls, 34.0760, -116.8876, coll. M. Hedin, 10 July 1993 (SDSU_H0025-0027, 3I). San Bernardino County, San Bernardino Mountains, Hwy 38, tributary into East Fork Mountain Home Creek, in culvert and tunnel under highway, 34.1198, -116.9768, coll. E. Ciaccio, 4 August 2018 (SDSU_G2897-2899, 3I). San Bernardino County, San Bernardino Mountains, Hwy 38, tributary into East Fork Mountain Home Creek, in culvert and tunnel under highway, 34.1198, -116.9768, coll. E. Ciaccio, 27 Sept 2018 (SDSU_G2929-2932, 4M). San Bernardino County, San Bernardino Mountains, Hwy 38, Forsee Creek, along stream and tunnel under highway, 34.1574, -116.9315, coll. E. Ciaccio, 4 August 2018 (SDSU_G2893-2896, F, 3I). See also Suppl. material 2 for locality (including elevation) and natural history information for specimens examined.

Remarks.

Catley (1994) hypothesized the following diagnostic features, based on comparisons to near-type locality H. petrunkevitchi :

" The species most closely resembles its sister species Hypochilus petrunkevitchi in general coloration, eye dimensions, and male pedipalpal morphology. Males can be recognized by the apex of the conductor which is more loosely whorled (fig. 24) than in H. petrunkevitchi , the shorter pedipalpal tarsus, a greatly reduced distal palpal (conductor) apophysis (fig. 25), and a median palpal apophysis that is significantly smaller than H. petrunkevitchi , with no notch (fig. 7). The short palpal tibia is strongly incrassate proximally. Females … are particularly difficult to separate from H. petrunkevitchi females, the former possessing similar but smaller convoluted spermathecal ducts (fig. 11)."

Our comparisons of near-type H. bernardino to larger samples (Suppl. material 2) of more northern populations in California (not including the distinctive H. kastoni ) suggests the following character trends. Regarding the shape of the apex of the conductor, we find no consistent difference in tightness of the whorls (Fig. 10 ), a feature that we also found difficult to characterize. The small distal conductor apophysis is likewise inconsistently absent or barely present across populations (Fig. 10 ). We also could not discern a consistent difference in the shape of the median palpal apophysis (Figs 11 , 12 ), with our SEM imaged H. bernardino specimens appearing much like the original drawings of H. petrunkevitchi ( Catley 1994: fig. 8). Differences in the degree of sclerotization at the base of this apophysis also makes the narrowness somewhat subjective to score, at least in some specimens. Finally, we found female spermathecal morphology to be highly conserved (Fig. 13 ); it is possible that the median ducts are more convoluted in H. bernardino than in northern populations, but this difference is subtle given our sampling.

Distribution and habitat.

Known only from two primary forks of a single drainage basin (headwaters of Santa Ana River, and Mill Creek, a large tributary of the Santa Ana), south side of the San Bernardino Mountains of southern California (Fig. 9 ). The Forsee Creek population, near the headwaters of the Santa Ana River, represents a new record for this species. We suspect that additional populations likely exist in the narrow canyons that lead into the Santa Ana River, for example, Bear Creek, Warm Springs Canyon, etc. In our recent collections we have found spiders in webs on large, sheltered granite boulders near streams, and in stream culverts beneath a primary highway.

Conservation.

We view H. bernardino as a short-range endemic taxon with a precarious future, deserving of special conservation attention and monitoring efforts. Over 25 years ago, Catley (1994) discussed how populations may have been negatively affected by drought. More recently, large fires have burned the forests of the Mountain Home Creek drainage (e.g., 2018 Valley fire). The loss of forest canopy cover is expected to result in fundamental changes in microhabitat conditions, and in concert with increasing global temperatures, calls for continued close monitoring of H. bernardino populations.

Figures

Figure 9. Southern Sierra Nevada topography map with genetic and morphological sample locations (see Suppl. material 1 and Suppl. material 2). Geographic gaps and other notable geographic features mentioned in the text are highlighted.

Figure 10. California taxa male palp (conductor) comparison. For each specimen, left panel = prolateral view, right panel = retrolateral view. H. bernardino A, B Mtn Home (SDSU _ G 2931) C, D Mtn Home (SDSU _ G 2932); H. xomote E, F Alder Creek (SDSU _ G 2600) G, H Tule River (SDSU _ G 2289); H. petrunkevitchi KINGS lineage I, J Mill Flat (SDSU _ G 2554); H. petrunkevitchi KAW lineage K, L Mineral King Road (SDSU _ TAC 000192); H. petrunkevitchi YOSE lineage M, N Yosemite (SDSU _ G 2568); H. kastoni O, P Ney Springs (SDSU _ TAC 000191). Distal conductor apophysis highlighted by arrows. Detailed specimen information provided in Suppl. material 2.

Figure 11. California taxa male palp comparison, prolateral views. H. kastoni A Ney Springs (SDSU _ TAC 000191); H. bernardino B Mtn Home (SDSU _ G 2931) C Mtn Home (SDSU _ G 2932); H. xomote D Tule River (SDSU _ G 2289) E Alder Creek (SDSU _ G 2600) F Belknap Springs (SDSU _ G 2300); H. petrunkevitchi KINGS lineage G Mill Flat (SDSU _ G 2554); H. petrunkevitchi KAW lineage H Mineral King Road (SDSU _ TAC 000192); H. petrunkevitchi YOSE lineage I Yosemite (SDSU _ G 2568). Median apophysis highlighted by arrows. For specimens E and I the bulb has rotated during specimen prep; these two images are retrolateral views, subsequently flipped in Photoshop. Detailed specimen information provided in Suppl. material 2.

Figure 12. California taxa male palp comparison, retrolateral views. H. kastoni A Ney Springs (SDSU _ TAC 000191); H. bernardino B Mtn Home (SDSU _ G 2931) C Mtn Home (SDSU _ G 2932); H. xomote D Tule River (SDSU _ G 2289) E Alder Creek (SDSU _ G 2600) F Belknap Creek (SDSU _ G 2300); H. petrunkevitchi KINGS lineage G Mill Flat (SDSU _ G 2554); H. petrunkevitchi KAW lineage H Mineral King Road (SDSU _ TAC 000192); H. petrunkevitchi YOSE lineage I Yosemite (SDSU _ G 2568). For specimens E and I the bulb has rotated during specimen prep; these two images are prolateral views, subsequently flipped in Photoshop. Detailed specimen information provided in Suppl. material 2.

Figure 13. Comparative female spermathecal morphology for California taxa. H. bernardino A Foresee Creek (SDSU _ G 2893); H. petrunkevitchi YOSE lineage B Yosemite (SDSU _ G 2564); H. xomote C Jenny Creek (SDSU _ G 2477) D Windy Creek (SDSU _ G 2465) E Belknap Creek (SDSU _ G 2296) F Alder Creek (SDSU _ G 2601); H. petrunkevitchi KAW lineage G Ladybug Trail (SDSU _ G 2275) H Mineral King Road (SDSU _ G 2485); H. petrunkevitchi KINGS lineage I Mill Creek (SDSU _ G 2543) J Providence Creek (SDSU _ G 2508); H. petrunkevitchi SAN lineage K Snowslide Creek (SDSU _ G 2557) L Balsam Creek (SDSU _ G 2415). Scale bars shown for select specimens. Detailed specimen information provided in Suppl. material 2.