The Golden Gate Leech Helobdella californica (Hirudinea: Glossiphoniidae): Occurrence and DNA‐Based Taxonomy of a Species Restricted to San Francisco

Abstract

Leeches of the genus Helobdella are small brooding annelids that inhabit lakes and streams on every continent, notably in South America. The type species, H. stagnalis L. 1758, occurs in Europe and North America. Here I provide novel observations on the occurrence, morphology, and parental care patterns of the related H. californica, a taxon described in 1988, based on specimens collected in Stow Lake, Golden Gate Park, San Francisco. In 2007, the original H. californica population no longer existed, possibly due to eutrophication of this popular "duck pond". However, in other, cleaner lakes of the Golden Gate Park dense, stable populations of H. californica were discovered. Between 2007 and 2010 adult individuals were investigated in the laboratory with respect to their pigment patterns and feeding behaviour. The leeches suck the red, haemoglobin-rich haemolymph from insect larvae (Chironomus sp.) and other small aquatic invertebrates and feed their young attached to their ventral surface. A typical feeding episode is described and documented. In addition, a neighbour-joining analysis was performed based on a newly acquired DNA sequence of part of the mitochondrial gene cytochrome c oxidase subunit I (CO-I) for H. californica, combined with other, related leech species. These molecular data corroborate that the "Golden Gate leech" is a separate species and not a colour variant of H. stagnalis. Since, over the past 25 years, H. californica has only been found in the freshwater ecosystems of the Golden Gate Park, it is concluded that this rare leech is a species restricted to San Francisco.

Description of a new leech species from North America,Helobdella austinensisn. sp. (Hirudinea: Glossiphoniidae), with observations on its feeding behaviour

“…H. triserialis USA, Siddall & Borda 2003;Klemm et al 2012) and H. californica (Kutschera 1988(Kutschera , 1989(Kutschera , 2011, living freshwater snails appear to be the preferred host organism of H. austinensis n. sp. Our prey selection studies revealed that H. austinensis n. sp.…”

“…Therefore, it is conceivable that the species discovered in Austin, Texas, is an imported leech from South America. Circumstantial evidence suggests that the taxa H. europaea and H. californica, which are distributed in aquatic freshwater ecosystems of Europe, Australia, New Zealand, South Africa, Hawaii, Thailand, and California, respectively, are likewise imported species from South America (Kutschera 2004(Kutschera , 2011. On the other hand, phylogenetic analyses document that H. austinensis (i.e., "H. robusta TX AU1") resides in a monophyletic clade of North American Helobdella species (Oceguera-Figueroa et al 2010).…”

“…); other potential host organisms (water snails, crustaceans) are only accepted when these "worm-shaped" prey organisms are not available (Sawyer 1972(Sawyer , 1986Kutschera & Wirtz 2001). Under the same laboratory conditions, the invasive leech H. europaea and the North American H. californica fed on living Chironomus larvae and agile crustaceans, as did the type species H. stagnalis (Kutschera 1989(Kutschera , 2004(Kutschera , 2011.…”

The European medicinal leech Hirudo medicinalis L.: Morphology and occurrence of an endangered species

“…Based on CO-I-sequences acquired in our laboratory for H. verbana and other leech species (Kutschera 2010(Kutschera , 2011Kutschera et al 2007Kutschera et al , 2013, supplemented by additional GenBank CO-I-data, the results shown in Table 1 were obtained. The type species H. medicinalis and its sister taxon H. verbana differ by ca.…”

“…While the first taxon, the type species of the class Hirudinea Lamarck, 1818 (sangsue médicinale, i.e., the medicinal leech), is still accepted today as a valid species, Lamarck's "H. sanguisorba" remains an enigma. and Kutschera 2011;Elliott and Dobson 2014). Utevsky and Trontelj (2005) provided a key to all known European species in the genus Hirudo, and Kutschera (2012aKutschera ( , 2012 summarized their geographical distribution.…”