Acryptolaria tortugasensis Leloup, 1935

Peña Cantero, Alvaro L., Marques, Antonio C. & Migotto, Alvaro E., 2007, Revision of the genus Acryptolaria Norman, 1875 (Cnidaria, Hydrozoa, Lafoeidae), Journal of Natural History 41 (5 - 8), pp. 229-291 : 265-274

Acryptolaria tortugasensis Leloup, 1935

( Figures 14 , 16F , 18F , 19G ; Table XIV)

Acryptolaria tortugasensis Leloup 1935, p 13 , Figures 3 , 4 ; Bouillon et al. 1995, p 51.

Material examined

Holoype: IRSNB, IG 10497 , 10 June 1925, Tortugas, Florida, USA, one colony (alcohol) and two microslide preparations .

Description

One colony composed of a distally truncated, erect stem ca 60 mm in height, completely polysiphonic except for distal ends of branches. Main stem giving rise to lateral branches in approximately one plane, usually in an opposite or sub-opposite pattern, but with irregularities. Branches directed upwards with an angle of ca 60 ° or larger. Lateral branches polysiphonic, up to third-order, usually alternate or sub-opposite in one plane.

Hydrothecae alternately arranged in two planes, forming a wide angle, sometimes close to 90 °. Hydrotheca cylindrical, straight at adnate part, strongly curved outwards when it becomes free. Free part of adcauline hydrothecal wall convex. Abcauline wall straight basally, becoming concave at distal third with a marked inflexion point associated to a conspicuous internal cusp. Hydrothecal aperture circular, almost parallel to long axis of branch. Rim even, though slightly everted, with one or two short renovations.

Coppinia not observed.

Remarks

Although this species has been considered conspecific with A. conferta by several authors (e.g. Fraser 1944; Vervoort 1968; Calder 1991), it can be distinguished from all other species. Acryptolaria tortugasensis is unique in the internal cusp present in the abcauline hydrothecal wall. It is also characterized by the obtuse angle, close to 90 °, formed by the

alternate hydrothecae. It is also the Acrytolaria species with the largest nematocysts (cf. Table XV).

Distribution

Acryptolaria tortugasensis is only known from Tortugas, Florida, USA.

Key to the known species of Acryptolaria ( A. andersoni excluded)

1. Hydrothecae abruptly abcaulinarly curved............ 2

– Hydrothecae homogeneously abcaulinarly curved......... 4

2. Hydrotheca curved once............. A. rectangularis

– Hydrotheca curved twice. Abcauline wall with a sharp invagination at approxi- mately half of its length................. 3

3. Adcauline wall with a strong invagination at approximately half of its length..................... A. angulata

– Adcauline wall without that invagination......... A. bulbosa

4. Diameter of hydrothecae clearly smaller at adnate part........ 5

– Diameter of hydrothecae more or less constant throughout....... 9

5. Basal part of hydrothecae bottleneck-shaped......... A. gracilis

– Diameter of hydrothecae in adnate part decreasing towards hydrothecal base (hydrothecae horn-shaped)................ 6

6. Hydrotheca large. Diameter at aperture.300 Mm...... A. corniformis

– Diameter at aperture,300 Mm............... 7

7. Half of adcauline hydrothecal wall adnate to internode. Free adcauline wall more or less straight................. A. longitheca

– Two-thirds of adcauline wall adnate. Free adcauline wall convex..... 8

8. Length of abcauline hydrothecal wall,1000 Mm. Length of larger nematocysts.19 Mm.................... A. conferta

– Length of abcauline hydrothecal wall.1000 Mm. Length of larger nematocysts,17 Mm.................. A. crassicaulis

9. Diameter of hydrothecal aperture up to 160 Mm.......... 10

– Diameter of hydrothecal aperture larger............ 12

10. Length of adcauline hydrothecal wall.1000 Mm....... A. flabellum

– Hydrothecae tiny. Length of adcauline hydrothecal wall,800 Mm... 11

11. Four-fifths of hydrothecal adcauline wall adnate. Length of larger nematocysts.25 Mm.................... A. minima

– Two-thirds of hydrothecal adcauline wall adnate. Length of larger nematocyst,19 Mm.................... A. minuta

12. Hydrothecae alternate in two planes............. 13

– Hydrothecae alternate in one plane.............. 14

13. Hydrothecae with an abcauline internal cusp. Length of larger nematocysts.28 Mm................... A. tortugasensis

– Hydrothecae without cusps. Length of larger nematocysts,15 Mm.................... A. operculata

14. Two-thirds of hydrothecal adcauline wall adnate. Length of larger nematocyst,12 Mm.................... A. abies

– Three-quarters to four-fifths of adcauline wall adnate. Length of larger nematocysts.20 Mm............... A. pulchella

Figures

Figure 3. Acryptolaria bulbosa (Stechow, 1932). (A) Part of branch showing hydrothecal arrangement; (B–D) hydrothecae. All drawings from the holotype. Scale bar: 400 Mm.

Figure 4. Acryptolaria conferta (Allman, 1877). (A, B) Branch fragments showing hydrothecal arrangement; (C–F) hydrothecae; (G) gonothecae. All drawings from the holotype. Scale bar: 1 mm (A, B); 400 Mm (C–G).

Figure 14. Acryptolaria tortugasensis Leloup, 1935. (A–F) Branch fragments showing shape and arrangement of hydrothecae. All drawings from the holotype. Scale bar: 1 mm (A); 400 Mm (B–F).

Figure 16. Hydrothecal arrangement in Acryptolaria (continued). (A) A. longitheca; (B) A. minima; (C) A. minuta; (D) A. operculata; (E) A. pulchella; (F) A. tortugasensis. Scale bar: 500 Mm (A, D); 250 Mm (B, C, E, F).

Figure 18. Shape of hydrotheca in Acryptolaria (continued). (A) A. gracilis; (B) A. longitheca; (C) A. minima; (D) A. operculata; (E) A. pulchella; (F) A. tortugasensis. Scale bar: 100 Mm (A, C, F); 250 Mm (B, D, E).

Figure 19. Shape of gonothecae: (A) Acryptolaria conferta; (B) A. minima. Detail of different structures: (C) bottleneck-shaped basal part of hydrotheca in A. gracilis; (D) opercular structure in A. minima; (E) opercular structure in A. operculata; (F) longitudinal striae in hydrotheca of A. flabellum; (G) intrathecal cusp of A. tortugasensis. Scale bar: 100 Mm (A, B, D, F, G); 50 Mm (C); 250 Mm (E).